This is what I briefly mentioned earlier first you need to decide who your runners are then you can start working with the opposition in any meaningful sense. For this if we're ignoring the descriptive text and looking at dice pools we still need to define what we're working with at that level. I assume (correct me if I'm wrong) your dice pools are meant to represent a general "threat" category since you go 1-6 (as the threats in the book are classified) and not 1-12 as the skills are In which case I'd suggest looking at the book for general dice pools. You could drop rating zero since that's not so much a threat as more collateral damage waiting to happen. Now with the dice pools I'm assuming your values Deathstrobe are the total dice your rolling? In which case I'd bump them up a bit since even the common street gangs in the book at rating 1 are a DP of 6-8 to roll. I think the issue here is that each threat category upgrade doesn't translate to a DP upgrade. For example the dice pools for rating 1 (untrained street hood) and rating 2 (security guard) aren't that different however the security guard has access to heavier weaponry (automatics) and magic which makes them more of a threat even though what they're rolling is still in the 6-8 range its now 6-8 emptying a light machine gun at you or casting a spell to buy time for reinforcements to show up. Which brings us to 3 police and law enforcement units they're actually a bit of a step down in terms of gear/dp compared to security guards but they now add augmentations to the mix upgrading their abilities there. Then at rating 4 we add decking capabiliteis and a dp ugprade. After which there's a big jump to 5 elite corp security (the guy's responding to the alert from the rating 2 ones who have another DP ugprade and better cybergear again. Then finally at rating 6 we get another dp and gear upgrade in addition to magic (I just noticed the lieutenant is actually initiated so there's definately no way a now runners at this level).
Anyway this makes trying to go by simply DP a problem as you need to consider all the factors making it something more like . . .
1 = 8 DP no augments/awakened
2 = 8 DP low level awakened
3 = 8 DP low level augments
4 = 10 DP, mid level augments and awakened (rare)
5 = 16 DP, High level augments and awakened (common).
6 = 22 DP, Anything goes (all).
And as you can see that runs into problems as for the first 3 ranks of challenge your looking at a roughly simimlar dice pool but their other capabilities change significantly. The rating 1 foes are just ordinary metahumans with poor quality gear by and large, at level 2 you start encountering awakened and better quality gear, at 3 you run into augmented foes so while they're dice pool hasn't changed they might now be able to see heat signatures or not be affected by poisons. At level 4 we finally see a dice pool upgrade but more importantly the augemnts and awakened they use become more powerful as well. At 5 and 6 everything goes up. Then on top of this the nature of the foes changes as well for the different ratings. Common street trash are as likely to come after you to prove themself as they are to run and hide from your threat, corp security just fight a delaying action waiting for help and are very unlikely to pursue, rating 3 will call in LOTS of backup, hunt you down and try to incarcerate you. Level 4 could be anything from hiring higher level muscle to hit you down to trying to buy you off depending on the organization in question but are more likely to threaten your friends and family. Level 5 are going to try and kill you but are only likely to pursue if you got away with something you shouldn't have. Its all over the place.
Honestly I think I'd prefer to go with more a skill based system if we're changing things something like . . .
Skill Rating 0: N/A
Skill Rating Competant = common threats.
Skill Rating Professional = Organized Threats
Skill Rating Elite = Elite Threats
Skill Rating Legendary = Special
So if the groups highest skill rankings or highest specialization are at that level then you throw threats of that nature against them. To give examples.
Highest Group skills = 3 they are competent but nothing special (street scum games) and will be facing common threats (street gangs, low level security forces, police or reflavoured versions of those).
Highest Group skills = 6 they are professionals (normal starting level) and will be facing organized opposition (all the common threats plus organized gangs who actually try to counter them or reflavoured versions of same).
Highest Group skills = 10 or maybe 9 they are elite they don't need to look for work it comes to them (prime runners) and will be facing threats that'd make even most runners back off (assasinating a corp exec when he's travelling under guard to a highly secured facility in one of 3 convoy's and a a helicopter, elite security forces protecting the base itself and in all the convoys, less than a 24 hour window and so on).
Highest Group skills = 11+ they are legends in their own right e.g. fast jack and shape the fate of the world on a regular basis. If you have to ask what they're doing your not ready to do it.
Probably not the best layout as its 2:30 in the morning but what I'm getting at here is you match up how skilled they are against what they're facing. Anyone might be facing a group of gangers doing a drive by shooting as an initiation, the normal players still aren't facing extremely high dice pools but they can be running into deckers, awakened and augmented individuals plus they're dealing with groups who will take the time to try and hunt them down for revenge not just an indviidual here but organizations who have deckers on staff to pull who your friends and family are if they can ID you. Prime runners are going up against elite special forces and security troops. Legendary runners are going after world threatening forces of nature and usually are doing it because of personal desire rather than any need for funds. If the party samura has a skill of 6, rating 6 ability and specializing for a starting pool of 14 (plus any other modififers for gear/augments) and the rest of the party's the same in their areas you can use common and organized threats to wear them down and elite individual as the big bad's dragon so they have to plan and think to take him down.
To illustrate this the runners with 14-16 dicepools in their primaries have been hired to take down a SINless slaving ring its mainly composed of organized oponents mid level augments and awakened here and there as well as a dice of 10ish which they can handle reasonably easily but it wears them down a bit on top of which the local police are also involved protecting the "legitimate" business again the "terrorists" and your client doesn't want the officers hurt. Then the bosses enforcer steps in personally. He's the equivilent of an elite secuirty officer with a dice pool in the 16's with lots of high tech armour and weapons. Yes they can take him but they'll get hurt doing it and then they have to go after the boss who's back down a rating as he's less of a direct threat and more of a thinker. Later when they're skills have increased they aren't going after an organized crime gang they need to extract the target from a group of elite security officers (24 of them although only a third are on duty at any time) under a lietunant with orders to kill the target rather than let him be taken.