I don't think of White or Theis as saviors for the team, at all. I do, however, see them as perfect fits for this team. They are very good complimentary players to Tatum and brown.
Theis plays hard on D, sets very good screens and is completely unselfish. Tatum was interviewed recently and he just smiled when he was talking about Theis being back on the team.
Derrick White will be very good next to Tatum and Brown - he is also unselfish and will look to make the right pass, a lot.
Tougher, meaner, stronger, grittier? Absolutely. Ainge loved centers under 6' 9" and guards under six foot and we constantly got mauled by other teams because of it. Kemba versus Smart and White at the point? Yeah, I'd say we got massively tougher at the position this year. Udoka has also gotten into the heads of GWilliams, RWillimas and Tatum and Brown about being tougher this year and they have all made strides in that area - which is why we've been so tough defensively the last month+, it's called progress. It's called changing mindset and changing the mental DNA of the team. Look at the roster - nearly every guy on it is similar is in level of effort and grittiness.
As far as Ainge being a Shark versus Stevens. I think anyone who's ever done business at even half of a high level, hates dealing with a guy on the other side of the table you think it's constantly trying to screw you/out do you/win every single deal. It sucks - a lot, and you'd much rather find companies that are reasonable to deal with. I think Stevens has a very, very clear vision of what he wants to do and is willing to give some things up to get it. That's good business.
Seriously, how is a pick in the 18-24 range going to help Tatum win a ring in the next three years?
Ainge was very good at the big picture stuff but I thought his drafting left a lot to be desired and his moves around the fringes to tie out the team were terrible. it was no different with the KG/PP/Ray Allen team. After Rondo and Perk we usually sucked coming off the bench and it probably cost us at least one ring. To me, Stevens is far better at making moves around the edges and he's willing to give up a meaningless second round pick to get a half decent role player.
Further, Ste4vens apparently does not like to watch guys walk in free agency for nothing. We had a literal parade of guys walking every year with zero compensation back, which is how we went from a top three team in the east to a team fighting to make the playoffs:
Horford, Hayward, Irving - zero compensation back. Brutal.