When Saruman was making the Uruks, I was both enlighted and grossed out. They are very strong, but the way he made them... uhh.
For those poor enough, desperate enough, or disgusting enough, I suggest a way to obtain this unit freely, (although, if you ask me, this is much more hassle than just paying some twenty-thirty coins for an uruk.) You start with +500 alignment with uruks. Then, you go and make a cave in some evil orc faction land, in between levels 10 and 45. Once there, you need to make a 1 deep, two tall hole into the wall, and place two pieces of quagmire in there. Next, you need: 10 orc bones, ten rotten flesh, three man flesh, and an orc draught. You right click all of these things into the quagmire: first, the bones, then, the rotten flesh, then the man flesh, and finally, "pour out" the orc draught onto the top piece of the quagmire. Once all of it has been placed in, both blocks turn into an entity (which can be killed with one punch) but looks like two pieces of quagmire, with bits of bone, rotten flesh, and meat. (plus a reddish tint from the orc draught). This entity will be called Uruk-Mud, (but please feel free to comment below what it should be called. I honestly dont know) For the next three minecraft days, you need to "feed" the uruk mud with three man flesh and one orc draught a day (the potency of the draught doesn't matter) On the third day, when you finish feeding it, it is done. You right click on the uruk mud, and out pops an armorless uruk! BLEAH! You now need to armor up the uruk in uruk armor, and give him a crossbow, or sword (your choice). He will have the same "controls" and GUI as a hired unit. Ta-dah! A free uruk! (Was it worth it?) Also, the quagmire can't be reused! :D