If people were upset about Kyrie's play last year, take this into consideration about Russell
1. Russell is a worse shooter than Kyrie from the field, the 3 point line and the free throw line and shoots the ball more than Kyrie.
2. Russell shoots more three pointers than Kyrie even though he makes less three pointers than Kyrie at a lesser rate
3. Russell avoids contact in the lane even more than Kyrie, getting to the FT line much less than Kyrie and making those shots at a much lesser rate.
4. Russell's defense is as bad as Kyrie's if not worse.
5. Russell is as ball dominant and isolation heavy as Kyrie if not more.
6. Russell, given his age and former locker room actions in LA, is no leader. His ability to eventually become a leader, may be on the same level as Kyrie.
7. Russell hasn't shown he can come up big when it matters most, in the playoffs. As bad as Kyrie's series was for Boston this year, Russell's was worse. But Kyrie has shown he can be phenomenal in the playoffs, even if he wasn't in the Milwaukee series.
If you didn't like Kyrie in Green, you should hate the idea of bringing in Russell. And, there is the possibility such a deal could hard cap the team, depending on what else has been happening in the off-season thus far.
I have been pretty vocal that I doubt Ainge does any sign and trades. Heck, teams across the league haven't made a single sign and trade in 2 years. I think the likelihood of a simultaneous sign and trade, especially between division rivals, is nearly zero.