Please don't, he'll do it
Okay. so
8gb was the Medium. Now i believe 16gb is truly the best point, in terms of ram.
Arma 3 is a CPU intensive game, so having more ram may not massively affect your experience. But it won't do any bad. You will notice improvements, of course putting your game on an SSD will also help it with things like stuttering.
I would personally always have 16gb of ram.