Help on Halo 3 Lengendary Campain ?

[Jack]

I did half the campain by myself but if i did the other half on co-op would it count as me doing the whole thing in lengenday, because i need the points for the security armor.
Well i ment, would i still get the gamerpoints if i did half by myself and half on co-op

 

[Tyler Durden]

u dont get armor by doing campaign u get it by getting the skulls

 

[Downfalcon]

My brother did it on split-screen by himself. I believe it counted.