I don’t think it’s a nonsense. There are several ladies in my ‘conservative church’ (LCMS) that don’t believe in abortion but want big government taking care. Or the other way around: I know some people who want small government but don’t care about abortion.
A government that is powerful enough to “take care” of people is strong enough to take away their liberty.
You seem caught up with the single issue of abortion. If, as you say, there are many small government types who don’t care about abortion, even though Roe v Wade is a big government power grab, what’s the big deal? If they don’t care about it one way or the other, but most of their political bedfellows (the social conservatives) do, what’s so horrible about working to help the team? Like you wrote, if abortion doesn’t really matter to them, but they want small government, what is the better approach? Join with liberals who are diametrically opposed to small government on nearly every issue, or work with social conservatives (who are mostly small government) to include helping them get what they feel is important?
You can’t just expect social conservatives to work on the things you deem important without it being a two-way street.