It does matter that it's Johnson over Stein. Johnson and his running mate were both two-term governors. If they make it to the debate stage, they are real candidates and nobody can dismiss them.
You (along with the immediate parent) actually do have a good point here. If any pollsters ask, I'd probably say I support Johnson for this reason, though overall I'd personally prefer Green policies over Libertarian ones. There's something to be said for Greens/Libs banding together just to help wedge third parties into the process at all. This kind of strategizing is still pretty unfortunate though, and only makes sense for the polling/debate process, not necessarily the electoral one.
Not to mention the CPD would almost certainly change the debate qualifiers immediately to still keep Johnson out, same as the DNC did with Lawrence Lessig.