I find the transition from tier 2 to tier 3 very hard. I adventured a lot in tier 2 and frankly it's too easy for me now. But tier 3 is still too hard. When entering a tier 3 zone, I get almost immediately jumped upon by multiple yellows (up to 5...). Even my archer cant pick them off one by one, because as soon as I hit one (from as far as possible) all others come after me too. Strafing isn't really possible either, because if I move back too much I'll run into for instance a group of bears. Now I'm not the best player when it comes to reflexes and so on, but I didn't expect it would get frustrating so soon. A pity, because otherwise it's a great game!
Yes, it is unfortunate. This is an issue in many areas. I recall being stuck there for a long time as well, and then very nearly skipping t4. And getting stuck at t5 forever, because back then, they went right from t5 to t10. Only suggestion I can really make is to seek out all the t3 scenes you can find; there may be one or two where the mobs are more spread out, or are a little easier than some others. The only other piece of advice I can offer is to concentrate progression on your base damage skill. (Sounds like you're an archer, so that'd be the base Ranged Combat skill.) Even if it means you're still stuck in t2 scenes for a while. If you're light armor, the armor skills really don't help much with actual damage mitigation, so you're better off getting to a point where you can out-damage stuff, and putting all your xp into the base combat skill will affect all the other combat skills in that school. Light armor archery only really works if you try and play as a glass cannon, sadly.
And don't forget defensive buffs help. Eat your food and get the blessing buffs. This all really helps.
True, but you'll still need to put that XP into some skills. Though, I suppose that can be done at a training dummy.