But considering Gundabad was originally built by dwarves and then occupied by orcs, i think it should have a more advanced look, like in the movie. Just like Minas Morgul was built by men and then occupied by orcs and started looking like a place of evil.
And the canps having the wild look, since the orcs built them themselves.
This would be lore friendly.
And Fredius made me change my mind about the armor. Bolgs army in botfa had heavy armor, but it was only on the chest, shoulders, helmet and shin pads, the rest was uncovered, with that armor you could see their unique look amongst the orc race.
And Melkor Bauglir, none was talking about the troll sizes, i agree they shouldnt be too large. But in the hobbit we must consider the trolls standing next to dwarves makes them seem bigger (but yes in some cases they seemed a little big) and if you compare the trolls in the hobbit at the time of thorins last charge they dont seem that large, to the moment in the return of the king when the three trolls enter the gate, those trolls look huge.
But back to the Gundabad fortress. Since Gundabad was an important fortress for the orcs of the north, i think it should be implemented. And the orcs probably made most their weapons there or in Moria, but since the team decided to go with Gundabad as the faction with a forge i do seem it fitting:)