Tamao deserved losing for not taking the initiative fast enough.
Should have done it before Nagisa completely fell for Shizuma.
Yaya too but she would probably still lose in the end.
I don't think you can really say who deserves what. Tamao did take initiative. She invited her to a romantic lunch date that Nagisa completely blew off to meet Shizuma, who acted creepy and intimidated her like usual.