The Mammon Machine doesn't have "bits," but I think it loses power during the course of the fight.
If I recall correctly, once you do enough damage to the Mammon Machine it says "the Mammon Machine stands still" or something to that effect, so I believe that's true. I could be wrong though.
I too love how they get easier.
Although I agree and it's that part of CT that makes gameplay enjoyable and not an absolute snooze, what RPGs make the main boss stronger by beating the parts of it??? I mean, I know that there are bosses that have stronger parts after you've beaten sections of the boss. I think that at least a few of FFVI's bosses were just like CT...
I don't believe that he's saying it
never turns out that bosses get easier in other RPGs, simply that it tends to not happen. There will always be exceptions to every rule, even in Chrono Trigger. For example, Lavos' first form gets "stronger" every time you beat one of its stages. However, in general Chrono Trigger bosses get easier as you continue to fight them (or stay the same) as opposed to getting harder, which is the norm in most other RPGs.