Maybe police could use Hunter without missiles, since the hunter is much more faster than seasparrow. Also the seasparrow isn't that much strong. It can be shot down easy with an M4, just aim for the rotor and it's down in a couple shots. An 1 v 1 Seasparrow vs Criminal on ground, the criminal would win easily ( try if you do0n't believe). It's very useful if it's used with squad support only, but can still be shot down easy with a good sniper shot.
I don't agree on the hydra tho, it would be too op in any case, especially if not both parts have access to it