re: Homemade Four Tortilla suggestions

Either of those recipes will work just fine; their ratios of flour:water:fat aren't radically different. The addition of baking powder won't tenderize the tortilla, it will just make it a bit flakier/have puffier bubbles when you cook it (baking powder is heat-activated).

It sounds more like a problem of under-kneading and/or using too much flour. An under-kneaded dough wants to stick to everything else, rather than stick to itself. You must manipulate the dough to the point where it is cohesive; don't just mix until the flour is moistened, but keep going: feel it change texture under your hands and become less sticky and more structured.

Regarding the too much flour, Alton Brown's recipe calls for 7 oz flour--that's 7 oz by weight, not volume. So use a scale to make sure you have the correct amount of flour. The other recipe calls for 3 cups: depending on how you pack the cup, you can end up with far too little or far too much flour. If you don't have a scale and must measure by volume, stir the flour, then sprinkle it into a dry measure cup (not a liquid volume wet measuring cup like Pyrex)....overfill slightly, then level it off with your finger or knife. This is far more accurate than sticking the cup into a bag of flour and pressing it against the side of the bag. Packing the cup ( x 3) can give you as much as 2-3 ounces more flour than you want.

Stuff like bread and tortillas requires craft knowledge--you need to do it repeatedly to get it right. Kneading is a skill learned with hands in the dough--or by closely observing the changes in texture while using a mixer or food processor. Don't give up. Flour is cheap, do it again and the texture will improve.

Also, resist the urge to add flour when rolling. Make the dough a tiny bit drier on your next go-round, and you won't need to flour it quite as much. Don't hurry the resting period after you divide the dough...the gluten you developed while kneading needs time to relax.