Assuming that I ask for a solution in FIFA 18 and 19 and the controls are the same, thanks to classic controls, so the solution will work for both games.
Can this be too broad given the circumstances, that the controls are indeed equal?
Is the same situation in two games too broad?
For example, this is pretty much what the <gamename>-series tags are for: questions that apply to multiple games in a series. The 'Too Broad' close reason states:
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once...
There's nothing there restricting you from asking the same question, about the exact same situation in two games.
However, a question asker should generally tag with the game they're playing and let the answers state whether it applies to other games too. I think that's the only hard and fast rule that can be applied here, and there are always exceptions. Your hypothetical question about controls that applies to both FIFA-18 and FIFA-19 probably wont apply to every FIFA game ever made, and thus I'd say tagging with a broad fifa-series tag wouldn't make sense there. Another example is the Sonic 3 & Knuckles situation, where two separate games can combine into one distinct game, so we have tags for all 3 and they are all applied as-needed.
So I see no problem with using two or more game tags if the question and answer is the same on both *, and it certainly doesn't make a question 'Too Broad'.
* Question askers generally won't know if an answer is the same on other games up-front, but it doesn't preclude the possibility of adding a tag as an edit later on should the answers apply to multiple games (or removing a tag should they not).
The post is asking two separate and unrelated questions: "How do you do X in Fifa 18?" and "How do you do X in Fifa 19?".
The controls are the same, thanks to classic controls, so the solution will work for both games.
That's an assumption about the nature of the answer, which has no impact when judging whether a question is on-topic or not. It could be due to a setting in some menu. It could happen automatically under different circumstances in both games.
As it stands, the question could have two unrelated answers, which makes it too broad for a single post.