Is sc2-build-order a legacy tag that should be deleted, or is there a reason it still exists?
I think it could be allowed to stay. It's a little general, but build orders are a big part of SC2 strategy, and I can see people using this tag, searching for it, favoriting it, etc.
On the down side, it is a little generic, and I don't think tags like sc2-strategy, sc2-micro, or in general gamename-tactictype are a good idea. I especially don't think we should have a build-order tag.
But as I said, build orders are rather key to SC2, and we have a lot of SC2 content so it's probably okay to have some sub-tags, like how Diablo 3 has diablo-3-monk, etc.
I do not see it adding any real value to the questions. Especially in its current form.
If it does not get removed (burning it would be my vote), maybe it should be changed to just [build-order] so it can be used with more than just starcraft 2 (other RTS games and MOBAs for example)
As-is it is used in 26 questions. There are 155 questions mentioning build order.