I don't think so. Is she soley responsible? No, but the song reminds me of crazy in love in that it was a bit borderline (the horns in crazy in love were great but the actual melody is dull) but the bridge was able to push it over the edge from being okay to good
Of course Maroon 5 would've reached the top. Payphone almost did, Makes Me Wonder did, and One More Night did (all for more than 1 week). Christina didn't determine the songs success. In fact, she should've gotten Adam for a collaboration for her album too (Adam/Maroon 5 >>>>>>>>>>>>>. Cee-Lo & Blake Shelton).