No need to change them yet. Going to multiplicative is a much better solution because it makes design decisions about indiviudal buildings independent. If we leave it addative it means you ALWAYS have to consider EVERY possible contributor in making design decisions (includng those from optional modules you may not even know you are going to add yet!), otherwise you can never be sure you won't approach or exceed 100%.
I will also look into why modern granary is not replacing the regular granary however.
Edit - the reason the granary is not being replaced is because it is not a 'real building' in the city. It's a free building given by the strategic grain reserve. The code doesn't cope with free buildings being replaced. I can fix this, but if I do it in the naive way (and doing it to avoid this will be quite hard) the consequence will be that it's gone for good in that city (so even if the modern granary got destroyed, the old style granary wouldn't magically re-appear just because you had a wonder that provides it for free). Only the city changing hands would cause re-evaluation of all the free stuff. This **MAY** be ok (it sorta makes sense in a real world model manner, since one imagines the old granary was bulldozed when the new one was built). However, its something I'd like feedback on. Making it work so that the free building gets replaced, yet still re-appears if the replacement gets destroyed is obviously also possible, but it's much harder to do.
For now I'm going to go ahead with my recommendation to make all the numbers multiplicative anyway, which reduces the significance of the granary stacking with modern granary, so we can defer changes for free building replacement (which way we decide to do it) until later.
Ah ha! So that's where the problem is. I think the Strategic Grain reserve should be changed then not to give a free granary but some other bonus and/or building.
Also when you say "multiplicative" what do you mean?
Like 50% x 10% = 5% ? In which why would anyone want to have a 10% building with a 50% building if its just going to reduce your food amount from 50% to 5%?
Or is it like 50% and 10% where 50% overrides the 10%. Thus using the larger %?
Personally I think we should just reduce the folllowing ...
- Storage Pit from 10% to 5%
- Granary from 30% to 10%
- Modern Granary from 50% to 20%
- Launch Arcology from 40% to 20%
- Colony Arcology from 50% to 25%
- Icehouse from 10% to 5%
- Warehouse from 10% to 5%
- Strategic Grain Reserve can leave at 20% but take out the free granary part.
Thus at max it would leave us at ...
20% + 25% + 5% +20% = 70% Which seems a lot better.
In short Koshling please leave it at additive. Just as long as the % get replaced by the replacing buildings or if the building goes obsolete.