Alliance are a serie of different mods. On the Star Wars GC, you can play the civil war Empire vs Rebel era + Black Sun and soon the Republic and CIS.
I needed some of time and many tweaks but you can see how now the original campaign from the game can be finished without problems. Of course I have made some changes on the missions.
Why is the Merciless firing at that weird angle?? :O
Because always it could make it. It is a problem from the game and not from the mod. You can check the original game if you want.
Should try to fix it. Though i don't have any modding experience, i'm guessing it's hard to fix.
That thing looks like a fancy UNSC Halo Frigate