I would prefer Blake Griffin to Drummond. Getting either would require trading Hayward (there won't be any 9 for 1 trades).
Blake Griffin "when healthy" is exactly what the Celtics need, a skilled athletic big (he is 31). The "when healthy" is a big if. He has averaged around 62 games a season in his career and will be yet again coming off an injury. 1 year plus a player option left on the deal.
Hayward "when healthy" is a skilled wing who can score and make things happen for others. He has his own "when healthy" concerns at age 30 and will likely be coming off an injury of one form or another for the rest of his career. He has one year option left on his contract.
I feel there is more risk with Blake over Hayward but also more upside and more upside at a position of more need. If he can hold up and run with our young guns for a couple of seasons, it could make a big difference. In 2018/19 for Detroit, he was 24.5/7.5 over 75 games and 35.0 min/gm.
It would be a big risk, but I prefer it to Drummond.