since it is intended to be a total conversion I'd simply increase the scale, in homeworld 2 I moved the HP scale from 0-100K to 0 - 50 million to accomodate the scale, so if I make the huge hulls have a 100K or more HP that should allow fighters with 1 hp
similarly with modifiers, if you extend the effective scale for the stat you have more resolution to play with, sensors could be class 18, but if that actual value makes sense in the mod then it is perfectly acceptable. this is why I am wondering if speed can be fractional (IE non-mobile ships would just have a speed of 0.0000000001 etc)
just because the devs enable a feature doesn't mean the stock game will have it, if modders can utilize it then it's valuable