I wouldn't consider getting rid of Mitchell. She put up outstanding numbers a year ago and I think is starting to hit her peak. Reminds me of Augustus at Minnesota all of those years--great scorer who isn't capable of leading her team to success her own but can be a huge weapon when surrounded by a couple of good teammates. Mitchelle and Smith were bright spots on a dreadful team. I like the core of Smith/Mitchell/Boston and think that'll be a great grouping long term.
I'm not really sold on anyone else on their roster though. Engstler was fine and has good glue player intangibles but I don't see her becoming a starter or double digit scorer in the league. Same with Hull who really struggled as a rookie, she could be out of a roster spot depending on how camp goes. Vivians hasn't shot the ball at a reliable clip since pre-ACL and I don't see her being a solution for Indiana as a starter. I like Egbo as a backup option off the bench, same with Tiffany Mitchell, but I don't think either is starter material. This draft isn't deep, but I think Horston or Jackson could be a good fit at 7, but I'm not sure either makes a difference long term. If Indiana could somehow get both Diamond Miller and Aliyah Boston I think that'd be a huge win, though the odds of that happening are slim to none. Looking at other wings, it just isn't a strong class. Jones is a good player but too similar to Engstler IMO and isn't an elite scorer, I'm not sold on Joens/Siegrist as WNBA players, and others like Blackwell, Berger and Madi Williams I see as second round players in most drafts. Plus all of those players could return for another year, so it's sort of a crap shoot to see who stays vs who declares.