Another question, and cant promise its my last.

I was reading more about fuses today and some people said that at the distribution block, don't put in fuses that are higher then the added sum of fuses on your amp. Now 4 Ga wire needs 100-125A fuse, So my alpine amp has 4x 25A fuses so 100A is fine for it, but then the 2 ch amp I'm looking at only has x1 40A fuse, it states it accepts 4 ga wire input, so I will use that. But I guess the question is, can I still put a 100A fuse at the distribution block for the wire leading to the amp. I'm thinking yes as i'm fusing for the wire's rating not the amp. But just wanted to check and get your opinions on it.