Feeling daft, I found the issue, I had turned off the setting to allow the user shares on the pools.
Edit: Squid just beat me to the first part of my issue
The reason I did that (a while ago) was because it seems to get really weird if there's existing folders on the pool (on pool two for example there might be a folder called projects, added via disk share before turning on user shares, this then shows as if it's a user share on the main array (under the cache column it says "no" despite the share being stored exclusively on a cache pool, if I create a new share manually on pool two, with cache only it says "Only : Pool_two" which is as I'd expect).
Can we disable shares for folders from appearing if we didn't explicitly create them?