Personally, I'd like to see a more Starcraft-esque system of doing things. This would make all infantry as one single soldier, and you can form squads by combining groups of marines. The exception is Mgalekgolo which would come as a bonded pair.
ODST (Can be dropped from orbit)
For the Covenant, a squad would have a designated leader; this leader could be upgraded to Chieftain/ Zealot/ Heavy. Alternatively, covenant could come in squads like HW1, and also e dropped from orbit in reentry pods. This would provide a nice contrast the UNSC.
Edited by BaconShelf, 07 August 2015 - 03:42 AM.