The last thread was about Spell critical strike. You now mean normal hits critical strike?
i don't know if you are an average map maker or not, but for me, yes it is possible, but it gonna work a lot to make it. If you are still new to WE, please don't try something that is too many work for yourself, try something easy first. And slowly improve it.
and regarding this post, please makes it more detail, regarding single target critical strike, it can be normal attack, passive attack(such as bash), or spell base(finger of death).