I'm going to start throwing out some specific ranges, because I think we're at the point where we can try to start defining some of these things. I agree with jas61292's post above, so I won't cover that ground again. I will say this though: if you want Physical Sweepiness to be high, you should explain why CAP 5 needs speed. Because from my vantage point, if we're serving as a wall, there's no need to be quick about it. Through the below estimates, I've barely considered speed as a factor, because I simply don't see the need for it. As soon as you start stacking it on, you run into issues of outspeeding other Pokemon, and that takes away from our true goal as a defensive pivot: to wall.
Physical Tankiness (PT)
Looking at our threat list, I don't think we want much here. I think right around Above Average to Good is what we'd like to shoot for. I don't think we should leave ourselves completely open to physical attacks, but it'd be nice to tank some non-super effective attacks. Pretty solid for a defensive pivot.
Physical Sweepiness (PS)
I personally will push for Below Average being our limit here, but I guess I could see Above Average falling in to the mix. I think it's sort of universally understood that we should be pushing our Attack stat for CAP5, so it's good that we set a flexible limit for PS. We should try to avoid going overboard, however. CAP 5 does not need to be a bulky attacker, so let's try not to enable that.
Special Tankiness (ST)
This should be set at Amazing, in my opinion. If we want to tank Latios, we should have some flexibility here. I think it's fine that most spreads run something around Fantastic level, but I am really loving the idea of a special wall for this CAP. If some people want to bum a stat in order to make ST shoot up to Amazing, I think they should have the ability to do that. Just please, don't go above 225 ST and have good stats elsewhere.
Special Sweepiness (SS)
Low. Non-existent. I'm thinking between Bad and Poor here. As soon as we make this level high, we're going to have big problems keeping Hidden Power off this Pokemon. Some of the Pokemon we want to be threatened by can get destroyed by a specific HP, so it's a top priority to have this effectively neutered.