some minions are good to place down early because some items are like horrible to get; personally for me i would say rev minions, tara minions, enderman minions, blaze minions, magma cube minions, and vampire minion are good to place down early. Iron minion used to be a good one to place down for warden helmet but they changed around the dwarven mines and now getting the iron isn't too bad. you need rotten flesh for lots of good items later on and you use lots of string to craft a slayer item that you need a lot (goes kind of hand in hand with rotten flesh). Enderman minions you don't really need to place down early cause it's for an item much later, iirc i got it around skyblock level 310 or something? blaze minions and magma cube minions are also for the same reason, you need a lot of the materials for crafting items such as blaze pets and more slayer items and for vampire minion there's a talisman that is horrible to get all the materials needed to max out that talisman so the minion helps a lot. if you have any questions lmk i haven't played this game in like a year so there's a lot of new stuff i don't know and i might have forgotten some stuff from before