Other tactics weren't working for me. Sablon vivant does well enough for me, as it has a couple of turns where it is faster than Bruce, which I found made things easier. This somewhat limits the AoE damage, as well as the healing the sharks can have when killing off your pets.
Sablon vivant having Tempête de sable helps mitigate some damage and by being ahead of Bruce it generally makes it somewhat more reliable.
Trait de sable helps against Maws Jr. as well as it means Sablon vivant is faster and is able to dish out some extra damage.
There's still RNG involved here, it seems that Bruce seems to go through patterns where he uses his attacks in a certain order for a couple of fights before he switches it.
Molosse du brasier shouldn't have too much difficulty against Maws Jr. Most successful runs Maws Jr. was already down to 3/4th if not half of his health.
I am going somewhat by memory here, I'll try to check if there's any major issues when he's next up.
At least one of the pets for this strategy require the use of a specific breed.
This strategy has been built to be as fast as possible.
The strategy takes a while. Sit back, get yourself a warm drink and relax the scenery.
Not every strategy can be bullet proof. This is one of them. You might have to restart it, since there are some random elements that increase the risk of your pets failing. Don't blame them, please!
You want a strategy that does the job in one shot? This might be the one for you!
Some instructions are more difficult to follow than others. That's exactly what you might find in this strategy!