You can do 4 achievements at the same time
Load up a player match with custom presets for instakills and instant respawn.
Put it on Death match with 60 kills and no time limit on Rooftop excess MP1 map.
Throw a time grenade (Hold LB and press X to select time grenade. Its then just LB to throw a time grenade) so you and your boosting partner are inside. Whoever is getting the kills first go for a head shot for the first 30 kills. Then for the following 25 kills get melee kills. Get 5 more kills any way you need to in case of mistakes and that will end the match.
All 4 achievements should pop.
Credit goes to HitHardTactics for help with the solution