AC vs HP decisions on p99 are generally pretty straightforward. On live after PoP I used a 10:1 ratio heavily favoring ac but in classic era timeline ac doesn’t seem to be nearly as potent.
For stats I shoot for a minimum always of str/agi: 85 agility (to swap in fungi), 150 strength. These benchmarks are easily met at the high level and once they’re met I tend to not bother considering these stats when making decisions.
This leaves stamina and dexterity.
I personally favor dexterity and will likely always. Some may balk at the idea ... but I lean towards 3dex to 1stam ratio. My magelo is below. My reasoning is pretty simple, at my gear and hp level my performance in groups and lower tier raids is not held back by a lack of hp but by threat. My goal is to hit 190 unbuffed dex so a single shaman buff has me maxed or close to it. Dex + focus stack would have me capped at 130-135 unbuffed dex but I don’t always have it. If I’ve done my best to maximize my threat, my group and raid mates are more free to do the things they need to.
If and when I jump into higher tier raiding, both dexterity and stamina will be easier to come by.
https://wiki.project1999.com/Magelo_Blue:Bedavir
I’ve got some crappy pieces that sorely need upgrading, but I think I’m doing well for a tank that has yet to attend anything better than a Kael plate house or Kael arena run.