Simmons isn't small for a combo guard and he is athletic he wouldn't be a terrible defender if he played in a switch system. A switch system works using quick similar built guys like Thomas. That's not hiding bad defenders it's making a system work for your players. Cs switched a lot and were considered a top defense. There are also reports RFA Thomas may play out the QO year. Given how late on the year we are that looks possible. Having a look at Simmons is a great option for the future decisions of the franchise and still being a decent club today. I never said anything about current existing contending teams that have no cap tading for Simmons either so not sure your point about that.
As for reports it's been said and hinted at by numerous outlets and coverage reporters. That "the C's are considering it" . Look at that Center group, the signings they made and the long wait to complete trades. They obviously aren't happy with where they are and the only thing they improved this year is their profit margin.
Trading Brown is a whole other thing. Everyone one goes right to Brown to get under the cap but there is a reason White trade offer was reported and I'll leave it at that.
At 6 foot 3 he is not short, especially with the wingspan, but I said smallish because he is so light he gets pushed around with ease, part of why he has been so bad on defense. Maybe being on a different team in a contract year will light a fire under him on that end but we just have not seen it yet and he is not old but he has played a prominent role in Portland for around five years. I have seen some Blazers fans on reddit and elsewhere saying he played better defense last year but he still was near the bottom of the league in every way that defense can be measured, and on a team that really improved into a pretty high level defense by the end of the year. Maybe a switching style helps a bit but my point was specifically that putting Simons and Thomas on the court together will not make either player or their team better defensively regardless of style.
I have not been big on the idea of Simons with this team long term because I do not think he can contribute to a winning team outside of a sixth man (or starter not finisher) role which is to me a $15 million salary tops. That said, it was not a bad return for a seemingly declining 35 year old with $104 million coming to him over the next three years. I expect it to be an overall downgrade even from what Jrue was last season but it does give some things the Celtics could use.
That, combined with the fact that I do not see a current market for Simons, leads me to tend to agree at this point that the Celtics might as well just try to get him into the system defensively and roll the dice over the first half of the season with him starting next to White and Brown with Pritchard maintaining the sixth man role but being much more likely than Simons to finish close games. Even with Tatum and KP gone, the presence of Brown, White, and shooters could give Simons some more room to operate than he had in Portland. If he can use that to increase his three point percentage back up to the 40 he was at a couple of years ago, then I can see him becoming an asset a contender might be willing to chase mid season. I just cannot envision his defense getting good enough to want to keep Simons at a number above $12 million (which I do not expect he would accept) so I still do not expect him to be a long term Celtic but at this point, unless a Claxton or Kessler can be pried with Simons as a primary piece (though I cannot see why Utah or Brooklyn would want Simons) I am content to see if Simons can increase his trade value.