Then it would appear the blocker, unless he can achieve a quick knnockdown, has to choose between keeping the opponent from moving south and keeping the opponent from moving west.
Many would advocate in such a situation that I get the blocker's head in front of the opponent, and use the far shoulder to make contact. I'd like to keep my player's head from being in front of a moving opponent wherever possible, and I'm afraid that getting his head sufficiently past danger would leave only the far, trailing arm to restrain the opponent from westward movement, and that arm
would have to hook around the opponent's near side to do so. So I think the type of angle block I want to do while being safe and effective would be more likely of the type I described previously, and maybe forego the arm in front of the opponent, turning it into a pure shoulder block, possibly supplemented by a chicken wing/flipper; but that makes for a narrower target.
Here's the video. Actually as I see it now, most of the time the blockers do manage to keep their forearm "inside" rather than wrapping around even the unrealistically thin dummy, although some of the time they do miss and wind up hooking the dummy.