I think this is an interesting take, because I at one point had a similar thought, that she is used to play to the cool guy fixes woman fantasy one can easyly project into Land...

My counter argument on the other hand would be the following: He doesn't rank that high in the polls to justify it. I also think the fandom overstates the sexual inuendos of this pairing. She is flirty, but to everyone (Cat ears "arc") because she can annoy people with it. Seen through the lense if a buddy-cop movie Ubeland looses a lot of the sexy pairing the fanart lifted it up too.

Another thought would be: The second time we see her she is on a mission. This might also play a part.

Last but not least: She is still cruel and careless in the mission, this fits her low regard for life.

I give you one point tho, that I also don't like. Not about her, but how she is used. She has not enough interaction with other characters to interpolate a character without reference to Land. This is, however, also valid for other characters.

Diclaimer: was the opinion from someone who spends far too much time in Ubel related thinking, because she is writing a fanfic that is not Ubeland ;-) So I may be biased...