After about 7 years of gargoyle keeping, I've decided it's pairs or singles, nothing else.
Females can get quite nasty with other females once they're breeding age. I guess they don't like the idea of him going out with that 'other woman' so they try to beat the living daylights out of each other. Sometimes they'll take it out on him as well for being the root of all the evil.
If there's enough space for the females to get away from each other, it might work, but it takes a big enclosure to give each her own personal space and even then it's not guaranteed to work. Once her hormones are in full gear, another female is a threat to her chance of passing on her own genes, so she'll do whatever she can to keep the male handy for her own purposes. Same deal as male to male combat, different gender.
And even if you keep just females together, same deal - the other female(s) are possible threats to her chance of passing on her genes. The fewer females around, the better her chances are of finding a mate.
Male-female pairs generally get along well enough. She just might eat his tail for a good supply of nutrients, but it's not guaranteed. I've never had a female do that to a male, but I've had females do that to each other, as well as bite toes off.
Gargoyles really are calmer than cresties, just as cute and lovable, but you have to set them up properly. They're a bit smaller than cresties in general, but that doesn't mean they need less space. For a pair, I wouldn't recommend less than a 20 gallon tank, lots of plants (real or silk) and bark slabs for hiding in and behind as well as lots of branches so each can pick a good place, no need to settle for leftovers.
And make sure the females are well fed. If they're full, there's less chance they'll feel like snacking on a tail. (BTW, gargoyle tails do grow back).