Might as well use a Pelta, then, with its built in little A-Wing hangar. I'd be more apt to buy one of those than a Neb.... oh, who am I kidding, I want BOTH.
The problem with those cards, Flashback, is that we've also seen the Ghost docking with a CR-90, so really, anything should be able to.
Docking at rest to exchange personnel and equipment is not the same as carrying something into combat at full combat thrust, probably making emergency maneuvers. One could reasonably assume that a dock that could hold onto an A-wing in combat could not keep the Ghost secure.
Although I've only seen a few episodes of Rebels and I'm not familiar with the context of the Ghost Docking to a CR90.