Absolutely C's can pass. Brown is a solid player about to hit his prime. Lillard has been seeing more injuries pile up. Brown is much more likely to have a better next three years performance wise than Lillard. Lillard also requires losing depth for any contender. It's going to be a hard move to trade for Lillard.
Not necessarily. If we could use Grant Williams in a S&T on around $17M-$18M / Yr (a big *if* because he would of course need to agree) then that would be a perfect salary match for Lillard.
That gives us a starting five of Rob Williams, Porzingis, Tatum, White and Lillard...then off the bench we would still have Brogdon, Horford, Pritchard, Brissett, Hauser, Kornet and any other Free Agents that Brad can potentially add in the meantime.
That is a REALLY strong and well balanced roster. You have good balance between inside/outside scoring, good balance between interior/perimeter defence, good overall balance between offence/defence in general, good balance between size/athleticism, and good balance between starters/bench depth.
Defensively it would be very tough to score inside against a rotation of Porzingis/Timelord/Horford, while Tatum and White on the perimeter would take a ton of defensive pressure off Lillard - just have Tatum/White guard the opposing teams best perimeter players and Lillard's defensive limitations would barely be a concern.
Offensively Tatum and Lillard would probably be the most ungardable duo in the league and would draw so much attention that Porzingis/White/Brogdon/Horford would be getting open looks all night long. Having Lillard also eliminates the need for Tatum to spend so much time as the primary ballhandler/playmaker, which means far less of those messy turnovers and forced plays.
And the fact that you have two starting calibre guys coming off the bench (Horford and Brogdon) also gives you outstanding redundancy to help compensate for the health risk of Porzingis and Lillard.
The more I think about this the more I'm actually starting to like it. I think this roster would have legitimate three-peat potential of all goes well, and could have the potential to go down in history as one of the greatest Celtics rosters ever. If they could manage to take home 2 or 3 rings with that team then it would all but guarantee Lillard and Tatum spots in the hall of fame as all-time greats.