Just started playing again for the first time 5ish years, on an unofficial Fjordur server with just a couple of other people. For boss fights is the standard composition still 18 Rex's, one Yuty, one daeodon?

Does it change at all if there's only one player going in with the tames?

Can I use any of the new creatures? The Deinonychus looks really cool with the bleed damage, anyway to get one of those tanky enough to survive a boss fight? The Magmasaur, Rock Elemental, and Shadowmane look awesome, are any of those viable for boss fights? And the Velonasaur and Andrewsarchus look like they would be super fun ranged DPS, if it's just me doing a boss fight alone could I use either one of those as my mount and get away with it?

TIA