As such you just pick the ones that have the most helpful colours on them for what you are doing
Endurance still sees healthy play, but only as a sideboard option
For example, your deck could contain lots of enchantments and artifacts to boost a relatively low number of creatures
The payoff of becoming a creature that gives all your stuff flying is pretty great too, even if its susceptible to removal
Beza will wreck house in Bloomburrow Limited, may be one of the best BLB cards in Standard, and might play well out of the 99 of commanders like Kynaios and Tiro of Meletis that can engineer that losing board state, but I dont see much hope for it in the command zone
Because The First Sliver decks win or lose based on the order of their buffs and because theres a lot of randomness to cascade, this decks either going to be super fun or super frustrating for you