Well, yes, their Antidermis would dissipate over time, but they don’t necessarily need outside aid to find a new body - they only need an empty one (for example Matoro’s body while he had used his Kanohi Iden, the Maxilos Robot that didn’t have a “soul” of its own, or the Great Spirit Robot in the short time Mata Nui was dead - I figure a Makuta could also inhabit a Rahkshi armor if one is nearby)
I’m still wondering how Teridax was able to cross such vast distances without a body (Mangaia ->Voya Nui, Voya Nui → Mahri Nui, Mahri nui → Metru Nui), though… because honestly, with a Makuta being able to travel such distances while in gaseous form it gets kinda weird that some Makuta actually died from not finding a new body in time.
Also there’s that alternate Universe where Matoro didn’t use the Ignika in time and Mata Nui died for real. There Teridax somehow managed to take over Icarax’s body.
Yeah, that’s the big question. In the end we probably can’t say if Tren Krom or the Makuta are more powerful from what we know in detail.
I personally see this as referring to the past - Tren Krom pretty much was the Great Spirit back then and as such could control everything in the Great Spirit Robot - like Mata Nui could and eventually Teridax could.
To get back to the topic again - Actually I liked that the G1 Makuta were a whole Brotherhood and not just one individual. Sure, most of the time it was only Teridax who mattered, but I think it would be nice to have not one evil overlord as the main villain, but a whole group of similarly powerful individuals that act as the bad guys.