Sales Engineers are a hard nut to figure out. If they’re too technical, they usually don’t have the polish they need to speak to prospects in the context of selling. If they’re too polished, they struggle to succeed in organizations that value technical skills. Soft skills are hard to quantify, so they’re hard to screen for, and even harder to cultivate. Probably why most of the really polished SE’s go onto become highly successful sales guys. Commissions are a great way to quantify results.