I would really like to see hero patron pools, but rather than individual patrons use organizations... PPD and Longbow are solid choices, and thematically make sense for pet summon powers as you would be calling in backup from your preferred group. Can even work on villains, just assume those are corrupt cops and renegade Longbow. I'm sure a couple others could be worked out to provide sets comparable to the villain patron pools.
And then maybe add two more patron pool sets... a Midnighter set with an arcane theme and a Vanguard set... both accessible through a new patron mission available through the Midnight Club (both hero and villain side) and in RWZ (also open to both). Heck, with the Temporal power sets (Defender/Corruptor/Blasters), maybe some additional new powers of a time theme could be worked out and create a new Mender patron pool accessible via mission in Ouroboros.
Over time, they could open up lots of different NPC group options that, even if there would be a lot of similar sets, they would offer a greater diversity of thematic approaches. Could be fun to have your villain show up on scene and then call for Freakshow or Warriors backup because he earned the loyalty of a few members, for example.