Conte doesn't look like he intends to use 433 a lot. He tried Litch and even Marrone as CBs just in order to keep the scheme. Isla is a winger, that's why he was signed. Litch is not a winger and played poorly in this position last season.
He's important for the squad, but isn't considered a starter anymore. Selling him could provide 2 good players in terms of rotation - Armero, freeing Asamoah to rotate in the middle - and the CF.
And as I said, if this can be done to get Jovetic, do it. This kid has amazing intelligence and creativity, what will be very important when Pirlo starts dropping his performances.
Litch is an important player for the squad and I like him. But if the outcome is Armero and Dzeko/Jovetic, it's worth it. You win more than you lose.