You're not wrong. You're right, as usual. There's more to it though.
The primary idea is to put a portion on the plate which the diner can cut into perfect bites with an appropriate table or steak knife. One of the first rules of carving is not to cut so thick that a lady cannot cut the meat, without undue difficulty, into pieces small enough to get into her mouth without disturbing her lipstick. If you can drill that concept into your husband's head you've not only struck a major blow against inconsiderate maleness, but for feminism as well. You go girl!
Of course, tenderness makes a HUGE difference. Tender meat is easy to cut on the plate and easy to eat as well. However, the tenderness of a given piece of meat is one of several considerations. You also have to decide whether you want to cut straight or on the bias; whether you want to cut with or across the grain; etc.
Meat which is so well cooked it's in danger of falling apart is often carved thick. Brisket gets that way sometimes, and sometimes not. It depends. Greek lamb is often very well done, so same thing. French "7 Hour" lamb is so tender it can be "carved with a spoon -- and if you CAN do it, then you SHOULD do it, because why not?
Bone a leg out, butterfly it, and cook it on the grill and it's a very different story. Carving starts -- or should start -- with breaking the roast into its constituent muscles and carving each into whatever thickness is most appropriate for a bite. You usually carve thinner if you're going to serve on bread, as for a sandwich.
There are an awful lot of cuts which qualify as "Chuck Roast," and they can be cooked in all sorts of different ways which lead to all sorts of results and which in turn lead to a variety of right ways to carve. It depends.
Ham, even very tender ham, is usually sliced thin. The idea there is not so much as to deal with tenderness but to keep from getting a mouth full of salt. But thinness actually tends to bring out flavor, so there's a balance. It depends.
Prime rib can be sliced thin, in the English style, or thick as we Americans usually prefer. It -- you may be sensing a theme developing, a leitmotif if you will -- depends.
Birds large enough to require carving, are usually best "broken," and the large pieces individually carved. Breasts are usually laid on the board, and carved on the bias across the shortest bias. The breast rule goes for turkey, chicken AND duck. Thighs, if large enough to carve, should be boned before slicing. Once boned, they are fragile and are best carved in whatever way you can keep some integrity for the slices. It... wait for it... depends.
A very sharp, efficient knife is a blessing. Longer knives usually make better carver/slicers than shorter -- but don't use anything that won't fit on your board or that's too long for you to handle comfortably. There's nothing wrong with an electric carving knife -- lots of people find them much easier to handle than regular carving knives; although, of course, they're aren't as elegant.
Edited by boar_d_laze - 1/11/13 at 10:01am