From the info that i've been looking into, Archery is now in the Warrior tree. Now most of the other skills that an archer would want to use is under the thieving tree. SO, if we choose to use the Thief stone, our Archery skills being leveled up will be moving too slow compared to our thieving skills. I feel that Archery being under the Warrior stone handicaps us. Why cant archery be under the thief as it has been in the past?

I feel that I'll be using my combat skills enough that it won't matter if I pick the thief stone (which I will). I'll be using my bow plenty.

^This

Whoa whoa whoa. You're acting as though there are only three guardian stones. It's been confirmed there are 13 different stones, each of which will give an experience bonus to a different set of skills. There will be a guardian stone for you, don't worry.

And in any case, people won't necessarily concentrate on ALL 6 of the skills they get the boost in from any one guardian stone. Just because you want to be a warrior, you won't necessarily concentrate on all 6 combat skills. There will always be one or two you miss out on.

Archery is technically a combat skill; if you shoot arrows at something, it generally takes damage. It was unrealistic for it to be a thief-aspect skill in any of the previous games.