it means separate from other search heads. This can be confusing in a small instance where you don't need to distinguish between search heads and indexers, but once you go to "pool of indexers with search heads floating on top" it starts getting clearer.
I did read that a separate SH is required. The way that is worded is confusing those.. separate from what? indexers or other search heads?
I will have a separate index cluster. My question is if there are any issues with having a search head that is NOT running ES along side one that is searching the same indexers. I guess the only other thing that ties them together is the license so just wondering if there are any issues with this scenario.