Stronger? Eh. Doubt it. But they definitely LOOKED more threatening. Benefits of coming earlier in the story and fighting weaker characters.
Unfortunately for Sommers and Killingham, Oda already fed most of the weaker SH's (+Jimbei) to Gunko for flexing purposes, so they didn't get to show off against weaker (but still notable) enemies too. So they didn't get to look particularly overwhelming. And then Sommers specifically just got bullied by top tier after top tier, until Oda let him fight Zoro.