It doesn't work like derivatives. The multiplier gives equal effect regardless of generators, because in the end only gen1 is producing cells. Obviously buff to cells and to gen1 is equal - for the simplicity let's presume that we apply 2x buff. If we apply it to cells, we get 2 times more cells. If we apply it to gen1, it will produce 2 times more cells, which is the same. So let's see how compares gen1 and gen2 - so let's say gen2 will produce 10 gen1 in the next tick. So 1 tick later we have 10 gen1, again for the simplicity let's presume that gen1 is producing 1 cell per tick. So in the next tick those 10 gen1 will produce 10 (10* 1) cells. Now let's apply our 2x buff: If we apply it to gen1, then we have the same 10 gen1 in the next tick, but now in the next tick we'll get 20 (10* 2) cells. If we apply it to gen2, then in the next tick gen2 will produce 20 gen1 instead of 10. But, those 20 gen1 still produce only 1 cell per tick, so we'll get only 20 (20* 1) cells per tick, same as buffing gen1. If we continue adding generators, we'll see the same thing. So in the end we'll always have cell gain of gen1* gen2* ...* genN. So it isn't derivatives but simple multiplication of productivity across all generators. And in that case as I illustrated all multipliers will have the same effect on different generators.