I think Udoka is a good coach. That doesn't mean that Mazzulla is a bad coach. As to HOU performance vs. BOS overall this season, I think a key factor is line up continuity. They have had their best unit for 416 minutes over 28 games. We have had our best unit (with Porzingis) for 208 minutes over 14 games. That is a big factor and makes it a lot easier on the coach.
In this most recent game, we played them with a very limited line up and almost beat them. HOU is a better team than BOS without White, Horford, and Hauser. Joe was able to cobble together some units with summer league players that held up pretty well. For example, a line up with Springer, Peterson, Queta, Pritchard, and Tatum was +5 in 3 minutes. In the end, we had a chance to win and didn't. It was good coaching that we were even in it right to the end, but bad coaching because we couldn't close the deal?
I think overall, people are too hard on Mazzulla. The grass is always greener when looking at other coaches. Joe has his flaws. his blind spots. But this game is a good example, he seem to get no credit for what he did with a limited line up last night but a couple of bad plays at the end and he is the dumbest coach in the world.