making all the ships with hangars would seriously increase a noticeable error on freespace....you can see this on cap ships or fighters depending on how you want to see this point, the problem is that either the fighters are too big or the cap ships are too small.
Taking in consideration the size of an Orion against the size of any fighter I would say that no more that 3 wings could fit in it, but cannon data from

would suggest that more than 3 wings are hosted inside an orion.
Also making the hagars would greatly increase the poly count of a model... I guess