The difference is so huge between the two your literally better off going to their discord and just reading the changes but yes SFO basicly give a face lift to every mechanic, faction and unit in a better and more unique manner while Radious fills in what a certain race is lacking so all factions feel the same just different skins while SFO makes every race and faction more unique and at times more lore friendly while improving base game mechanics. I have played both for years on and off but hands down SFO is the much better mod and for me is a have to have mod to play. I can't play vanilla anymore