This sounds like a workable concept
I believe that at the moment, the "ship variants" function only covers weapon loadouts. Perhaps in the future, the AI behavior of the ships will be somehow linked to that as well. We might also have AI officers with different personalities as captains of the ship, and the veterancy of her crew, to take into consideration.
i think currently the AI takes into account the weapon types you have on a ship to determine what its role is.
While I can see the utility of that arrangement, an alternative to what you suggested would be what I described above - the ship variant will dictate the behavior regardless of what changes you make to its weapon loadouts. Like, if a strike frigate is loaded with PD weapons, its still gonna go behaving like a strike frigate regardless. Could make for some funny/awesome/interesting combinations.
Also, tweak the awful interception pathing, which is currently a linear path to the target, rather than aiming infront of the target.
I'm hoping that more veteran or elite crews will be better at pathfinding like what you described, compared to greenhorns who might just go for a straight line. It'll elevate the importance of well-trained crew too