I guess the gear you logged out in atm is the gear with the stats you're referring to?
There are several benefits to avoidance:
1.You reduce the largest part of the bosses damage against you (almost all bosses ingame are at least 70% physical)
2. Your personal cooldowns and survival without healing can potentially be higher against certain bosses.
However, there are several cons to it too:
1. Your damage taken is very spiky. You'll end up potentially ooming healers because they waste mana panic-healing you (not so relevent in 70s content). Stamina just works better against this.
2. Effects that scale with health, don't really scale with avoidances. Because of avoidance capping in TBC, avoidances don't really get buffed from much anymore, besides the 5% stats buff.
From a warrior's perspective, stamina increases the value of second wind or any of your personal healing abilities, and also the value of last stand. Since warriors don't have shield barrier at 70 (the defensive skill that scales with attack power)
These days in wow, unless you're running content several tiers above your gear level (think 346 blues in heroic DS, but even then it's not as important), the high levels of damage reduction (ie stopping your char from taking damage) aren't really that important. Stamina is likely better in terms of removing the spikes.
Since you're a 70 twink, and are going into nerfed content with a health pool nearly at what 70 tanks had, it doesn't actually matter. However, in terms of actual stats, I'd go for something like capping hit and expertise (hit first, then get as close to 15% expertise as you can), followed by stacking as much stamina as possible. Generating more rage is probably better than having the biggest possible health pool atm, which will significantly reduce your damage taken via higher shield block uptime.
But hey, it's a twink bracket. Play how the hell you want, the content is easy. I'm just expressing how I would do it (with significant experience)
Hope this helped
P.S. you don't have to read the huge wall of text if you don't want to, just the last paragraph will do
