Well, if the whole team are playing riggers, you should look into diversifying character creation as much as possible.
Its no good having 5 riggers... its a lot better to have an adept wheelman rigger, an ork technomancer with sprite controlled drones, an elven face ares duelist rigger, an arial surveillance ace pilot etc.
Maybe you could hand out bonus skill points or bonus cash, with the intend to diversify the choice of riggers. I would definitely find it cool if the party could find room for both, mundane, adept, magicians and technomancer riggers.
That way you could have high.skill monkey adepts, machine sprites, some of those vehicle spells from street grimoire and a bazillion drones at the same time.
I run an awakened only campaign. We decided to move the special column in the priority system down one notch- which meant that at E you could become an adept, and at B you were a magician with magic 6 and 10 spells. This naturally made for stronger characters, but not as strong as prime runners. The team still has rigger/decker support and isnt hampered by "only" awakened.