For a new server with no service for POI or INQ I still checked out the new worlds and their forums to see what they suggest and they all suggest the bare minimum and I know you're not going on a service.
I know it's possible you can still go as minimum required which is level 80 for POI or level 100 for INQ. However, the ones blocking and killing it (which I'm sure everyone will pitch in to help) is really important. From what I understand for Inquisition - Elite Knights can be at least level 200 as a main blocker, a little under that for a second blocker if needbe, if there's just 1 main tank they usually suggest minimum of level 250ish. But if it's a new server, the higher the better, the more blockers the better because clearly theres more monsters than a knight can tank at times and with a low team you need to be careful.
.It all just depends on your team I think this question is very opinion based in the sense it depends on the players skills and levels and who is actually going. If you have more details on that we'd love to better assist you with your question. For POI it's less of a hassle so they recommend the tanker to be at least 150ish but same idea, more blockers and shooters the better!
https://www.tibia.com/forum/?action=thread&threadid=4754785
https://www.tibia.com/forum/?action=thread&threadid=4750575
https://www.tibia.com/forum/?action=thread&threadid=4750572
https://www.tibia.com/forum/?action=thread&threadid=4755593