They do come in different sizes, but the thickness of the wood should not be the determining factor. ALL hinges should be completely encased in wood. F'rinstance... if you have a built-up structure using a 3/8" hard balsa trailing edge and your hinge is 1/2", then prior to covering you should put a second 3/8" block inside of the wing at the hinge location. You can then make a 1/2" slot (or hole for hinge points) for the hinge and the full contact area of the hinge is glued and surrounded by wood, plus the load is spread out over a wider portion of the t/e. You also don't have to worry that all of the glue has been shoved into the wing, leaving nothing on the hinge... so don't double the 3/8" t/e and then cut a slot/hole that's 3/4" deep.

The size of the hinge is best determined by the expected per-hinge flight load. More hinges = smaller hinge needed... within reason. You could certainly get away with using 50 of the 1/2-A size hinges on an elevator half for a 33% Edge, but you've reached the point of diminishing returns. Same for CA hinges. I've built .25 size planes, hinging the elevator halves with two pieces of cut CA hinge (cut in half) and had no problems. I used Robart Hinge Points on the elevator/rudder of my Extra and DuBro pinned hinges on the ailerons. Would CA hinges have worked? Sure... but not half-size and certainly more than two per surface