I'm not an expert, you're going to want another opinion, but these are some observation-based thoughts on this.
If you look at tangs in a big tank, like public aquarium size, they swim in straight lines. That's why they need big tanks, they're more open-water than many reef fish. Angels do this as well, to some extent, but they usually spend more time weaving around rocks and corals than swimming around in open water. I'm not certain, but I believe they just need space in general, they don't need length space like tangs. For example, angels should be fine in cubes, tangs usually aren't. I'm not sure about a tall tank, but given that angels have a reasonably 3D swimming pattern (as opposed to tangs and their nearly-2D pattern), I think it would be okay.