Unfortunately, the swarm rules just don't seem to be very encouraging in terms of teaming up similar drones, especially armed ones as they'd only attack once if my reading of the rules are correct. Until Swarm is rewritten, I figure the below might be a good alternative for a rigger looking for some anthroform power.
Start with a basic MCT Kenchiku-Kikai for 20,000¥, increase its armor to 12 for 12,000¥, and Nonconductivity 5 for 2,500¥ and a Vectored Signal Filter for 1,300¥. Add your weapon (with mods) of choice.
Then add four MCT Fly-Spy mini drones for 2,000¥ each, and add Vectored Signal Filters for 1,300¥ each.
Get an RCC; for starting characters this is likely to be the Vulcan Liegelord for 66,000¥, and add the Vectored Signal Filter mod for 1,300¥.
NOTE: Vectored Signal Filters are only important if you expect noise, because a base K-K loses wireless connectivity in a Noise 3 environment which likely means it would lose it's connection to the swarm; with Vectored Signal Filters you are good until you hit noise 6. If however your GM reads the rules for noise as only the RCC needs to be able to reach your drones, a DR5 RCC with Vectored Signal Filter is good up to noise 8 and it would shave 1,300¥ off of the cost of every drone and the rigger could compensate on the fly for even more noise reduction.
Run EWar 5, Smartsoft, Stealth (Fly-Spy) 5, Swarm, and Targeting (weapon of choice) 5 for 9,600 total, or 75,600¥ for the RCC with programs.
For 42,500¥ in drones and 75,600¥ in electronics you've got an effective Device Rating 5 drone that rolls
Pilot 5 (nope) Agility 2 + Targeting 5 + Smartsoft 2 + Swarm 4 =
16 13 dice on the attack, Pilot 5 + Reaction 5
+ Swarm 4 =
14 10 dice on defense, and soaks anything up to DV 12 (-AP) without even rolling for it. As an anthroform with arms it has 8+Body/2=11 condition monitor, and because it's not firing a drone/vehicle mounted weapon it uses normal simple/complex actions to attack dependent on firing mode, and Strength 8 gives it 3 recoil compensation base and a few weapon mods easily adds enough for it to take aim and fire full auto weapon simple actions for maximum chance to hit (+1 to attack and +1 accuracy with smart weapon, as well as -5 to defense). With Nonconductivity 5 it stands a good chance to resist electricity damage, which drones are especially vulnerable to, and it is completely immune to stun damage.
Someone trying to hit the minidrones would be at a -2 plus -Speed, though suppressive fire could be potentially troublesome. That being said, run two swarms of these and you can put down enough suppressive fire on your own for when your team absolutely, positively have to go loud.
While I think it's a shame riggers have to resort to these kind of cheap tricks to make drones relatively strong in combat (unless you're playing in games where PCs regularly throw 20+ dice, the above drone both packs a punch and can take a hit), I'm quite happy with how a unit like this could function.
If nothing else, it should act as a great anti-theft security system for when you leave it in charge of the teams ride

What kind of drone swarms would you consider running as a rigger?