The point I think you are making is that anyone can rack up points for killing goblins and wolves, wizards can do those chores quickly( and yes it will count the same..)
But my guess( and only a guess ) is that those getting highly level achievements are going to have the value of those achievements weighted in the influence system. It is also my guess that basic weapon achievements are going to be low value like the t1 crafting achievements, anyone can do them with minimal xp. Elite ogre slaying is not going to be one of those.. And I think more to the point of how it relates to wizards, is a t2 wizard going to be able slay ogres in the same speed and manner as a T2 fighter / archer is going to be able to fight them?( who is going to survive a group of 2-3 ogres once robes are the only option?)
Granted this is based on what I think we will see once influence is published, but if the value of weapon achievements(any bow, divine, martial, crafting… ) is relatively low and the elite achievements ( elite knight, ogres, elite bandits. Etc) are higher I still do not get why you feel the speed of gaining lower level achievements is better boon than the speed of gaining higher level achievements. Anyone with the time can do the low level one with out much risk, while being a wizard doing the higher ones ( solo or in a pairing) is going to be much slower than the folks in the heavy armors and definitely have a ton more risk.
And as far as at present, them counting one for one … they don’t really count for much of anything except seeing large numbers in your achievements(except gating of roles if im thinking correctly.. and even then the gates are not severely out of reach for a character starting at 1k xp)