To add Beal, our team would be:
Room exception / Vet min / Vet min
Tatum / Vet min / Vet min
Brown / Nesmith / Vet min
Beal / Vet min / Vet min
Pritchard / Vet min / Vet min
That team isn't contending for a long, long time.
It seems more sensible to actually build a competitive team around players that other teams might actually want in trade.
I'd say it takes about a year based on previous teams who have gutted their rosters. That first year you lack the depth you need to win a title but by that second year you are right there.
You have that room exception MLE type thing, an actual MLE the next year, the LLE, another draft pick and a bunch of veteran minimum contract players looking to latch onto a contender.
So I'd say by year two we should expect a title contender after gutting our team to sign Beal.
Actually, due to having three players making over $94 million, that means the Celtics will never want to get hard capped. Which means only having Bird rights on your own free agent(which they probably won't have many, if any, of), the taxpayer MLE and vet min options as a free agent avenue to make the team better through free agency. A full MLE and the biannual exception(the LLE) hard cap teams, much like sign and trades.Trading vet mins and draft picks will be the easiest way to put competent talent around the team on a fast timeline.