Quite frankly, I'm not sure what the problem would be with a question about every other civ in AoE3? Spamming bad questions to prove your point wouldn't be productive; after all, they'd be bad questions that don't reflect research effort or experience or an understanding of what concerns the question ought to address most likely, but that doesn't mean that we can't have lots of them. Don't focus on how many variants of a question might exist (different divs, or build types or whatever). Consider the fact that the answers would be so wildly different that they don't start from the same place.
What problem exactly, are you trying to solve here? What I see is a reasonably specific question with a number of answers with quite a bit of specific detail in their responses. Are those responses appreciably similar to the answers you'd get for a question about playing AoE3 as the French or the Spanish or the Cree or the Iroquois? I don't know. I don't know enough about AoE 3 to make that judgment.
I can certainly say though, that if you'd linked say... a question about a build order for playing as Protoss in SC2, and asked if we should broaden it to include Zerg and Terran, I'd laugh in your face. If you'd linked a question about playing Civ 5 as the French, I'd probably argue to broaden it.
What I'm getting at here is that my answer to the previous question holds. Categorical statements are a bad idea:
Now, Build questions in general are a bit thornier, but again, a blanket ban is not the appropriate solution. Yes, a lot of character build questions are really bad questions; cf. skyrim. This does not make questions about character builds inherently bad. The main thing is that the question needs to reflect some actual experience - a concrete problem faced by the player. "I want a build that is totally cool and sneaky and uses big swords and magic lasers and stuff" is not a good question. It's unfocused, vague, and doesn't really provide any useful information for answerers to provide a good answer. The thing that gets tricky here, is that the criteria that separates a good build question from a bad one is very often specific to the game in question. A good build question for diablo-3 is generally going to specify a class, any skills that are 'mandatory' to the asker and must be built around, and a desired play style (tanky, hardcore, low-gear dependency magic-find, whatever). A good build question for mass-effect-3 by contrast, can generally be a bit more vague, and will generally expect it's answers to be as much or more focused on play style as it is on skill selection. Good build questions for skyrim tend to be either extremely specific (and focus on whether certain specific skills or spells are useful or synergize as they appear to), or very general and focused more on the meta-strategy of how to pick skills, rather than on particular skill choices. Good build questions about an MMO like world-of-warcraft will tend to be fairly mathy and depend on optimal DPS/HPS/Threat/Effective Health numbers - however, even with these, there may be multiple answers as different builds will make different tradeoffs and a multiplicity of answers arguing for these many variations is a good thing.
Is this question a bad question? I don't know enough about AoE3 to say. Do you? If so, make the case that it's a bad question, and that it ought to be fixed by being made broader. At the moment, you haven't done so at all - and the number and diversity of answers speaks to the fact that it probably shouldn't be, unless being made broader doesn't appreciably change those answers. Keep the usual heuristic for whether a question is too broad. Yes, some people like to, and are able to, write novels in response to questions. But any answer to a question ought to be able to stand on it's own; questions which compel either an extensive, extremely long comprehensive answer, or a 'one-per-answer' situation often end up being problematic.