Also any of the skulls can be turned on while you are doing these achievements, making them really easy. Like the 25% faster resources skull "bountiful harvest" for better chances of having the cash for a scarab.
If you are having trouble with the legendary AI achievement "One and Done". Go Prophet in a 2v2 preferably with a friend on the other team to "team kill" the AI. Turn some of the good skulls on "extra money,health,timers,ect" , and build bashes with boost and upgrade your Prophet so the he can cleanse the carrier if your AI teammate does in fact get the flag for the last point, before the time runs out.
Works really well got it on my first try.