Orca is a bit tricky espcecially if you want to factor in the trooper riding piggyback. It is also "overarmed" for its size. One of the examples where a "closed" game can trump an "open" one, even one as versatile as D:VG.
In practice, you'll have to abstract it somehow.
schuppiluliumas wrote:I will design them as a light vehicle with only two weapon slots: one heavy main armament and one HMG with an increased FR due to the additional light anti infantry weapon
As vehicles are at least SZ=4 the Orca is a tad bit small IMHO to be a vehicle. Of course SZ is not directly linked to the model size, but if you want to use "real" vehicles alongside it as well it might look a little odd. If you do go that route, I urge you to consider making the Orca into a mecha (doesn't look agile enough to be an anime mecha). You'll also have to note that light vehicles and mecha both only have 2 weapon slots in the first place, so you can't really utilize the full weapon load as individual weapons even in this case.
Another way to build the Orca might be to abstract it into a Crew Served weapon. That would probably be the angle I would use.
Got the weirdest feeling of deja vu about this post BTW. Must've written something very similar about a similar subject in the past, although can't conciously recall where and when. Strange how the mind works, ehh?