Well for races like the Terrenesi for example (reason I keep using them as an example is because they are going to one of "3" races in the Alpha release of the game) use light fighters as their main source of point defense against fighters while their PDTs are used mainly for missile intercept duty.
See what I was going for was so that (some races) Capital ship fleets would still need at least a squadron of intercept fighters to guard them from enemy bombers and fighters.
THEN you've got races like the swarmers (later release) who will have huge carriers and large numbers of (cheap but effective) fighters but their largest combat warship is a destroyer.
So you would have a large number of tactical doctrines available to you.
Oh and the "ship of the wall facing off" makes sense for the HH universe
