Sure beef her up and run her by me and I will go over her. Yes the characters are fine, the tiers are not for pairing around. It would impossible for your low tier to face any Intermediate tier and expect to win. Conversely your intermediate tiered partner has an undue advantage over low tiered opponents. In a fighting role-play like this strict adherence must be kept to ensure all fighters have a reasonable chance of winning against any other equal tiered character. Team fights have to be strictly monitored to ensure this occurs.

Several, perhaps three or more low tier can face a single intermediate tier with a chance of wining, and several intermediate tiered characters can face a high tier and expect a reasonable chance to win.