In halo 4 they should have an option were you can chose to play with computers and your friends. This will fill up the gap of player that aren't there. Sometimes all my friends are playing other games and only a few can play a custom game on a map i created and if there was computer players(bots) they could play and fill in the empty spots to make it more funner. To make it better there should be an option to make them easy, med, or hard. Just like in black ops where you can choose how many computer players you can play with.