i will say really really powerful.

Not really all that strong? Cuz remember broly lost to goku when goku was only ssj1? Absorbing broly might actually make him weaker just like when he absorbed 2 supreme kais

You mean the goku who had the power of 4 ss1's, 2 were fpss1's, and a super nemakian in one punch which caused his energy to leak out and explode? Lol thats funny.

I would say about the level he was at when he absorbed Piccolo, Goten and Trunks.

Super buu(gohan absorbed) is stronger than super buu(broly absorbed) because goku beat broly with the power of 2 fpss1's, 2 powered up ssj1's, and a super namek, all of which had close to no energy left(except vegeta, he was cowering too much to get beat up) while mystic gohan by himself is quite a bit stronger than a ssj3.