I am dreaming of a more orcish variant.
I once was an Ork player with around 15 000 points, about 5000 well painted, so that's personal.
There are freebooterz orcs with parrots on their shoulder and weapons that look very, very much like the ones used in Space Crusade.
Those have 40mm bases, so they are not too big for Space Crusade. Those are inspiring! In 40k they are just not good, but the models are great.
I could imagine a playcard "cunning taktik" "If an orc model would die, and there is a gretchin in less than 6 inch distance, remove that gretchin instead" like the matching 40k orc "tactic". That playcard, 2 or 3 times, then some creative rules for those Orc monsters.
Plus some additional standard orcs (variants with shoota, with rocket launcher, big shoota, burna); finally for good measure, two or three Meganobs (I would say those are harder to kill than a dreadnought, maybe one Life Point more, and stronger in close combat, while they have less shooting) and some normal Orc Nobs with close combat stuff on them.
I wouldn't introduce any Deff Dread or Kill Kan or similar stuff - their bases are just too big for Space Crusade, sadly. But I guss a Deff Dread, who can easily kill more than just one Space Marine squad, would be too strong for the game as well. You normally defend against those guys by not letting them come close - which is, of course, impossible in Space Crusade.
I once had a squad Kill Kanz with magnetized feet that I could use without base in Space Crusade, and magnetized arms so that I could attach what I want. Scrap gun, Big Shoota, Rocket Launcher, or extra close combat hand. They would be weaker than Dreadnoughts, with otherwise same-ish rules. Every hit removes a weapon, that makes two life points, 3 armour max. They never got to see their fight.