I think a Scarab boss would be pretty Yoinking awesome.
Flyable Pelicans I could see. But driveable Scarabs will never, ever happen.
I'm curious, what exactly are you seeing the Pelicans DO?
I mean, why would you want to waste/use your energy/cards on them?
Are they going to only transport people?
Okay, if they are only transporting, what is the point of using your energy/cards to move your troops around?
Are you going to require them to allow flags/bombs in this?
That wouldn't be very fair, now would it?
How would they counter said Pelican with the bomb/flag in it?
Would they just take the bomb, and then hover off shore/away from the other team?
You see the point here? It just isn't a feasible option, they can't really be balanced to make them worthwhile, and if they let them in, all they could do is make them a transport, of ONLY troops. What is the point behind that?