Yeah you come up just short of being able to buy the gasm falls trade even if you skip the ardford supplier if you insist on being perfect on battle of yhilin.
If you skip the ardford supplier, aramite supplier, and yhilin bank and buy the deeds of vinario to get megail 100, you will probably have 45000 ProN left after the ardford summit if you bought everything else worth thinking about.
If you have 0% discretionary and 5% personal funds left, that's worth an extra 2500 ProN in total.
You will be 17500 gold short of buying gasm falls trade post war in that case. You have a number of things you can skip to earn 17500 gold for that point.
Bridge+Yhilin Beautification frees up 10k, costs you 1 or 2 RP with Ginasta, but you have to spend an extra 10% in discretionary funds so it might only earn you 5k or 7.5k instead.
You can skip the IK cache, the stats it boosts aren't that useful and it's not used in any checks after that point. This frees up 10k but Simon will forever have less AGI than he could have had(The LUK doesn't really matter).
You can skip Arcane Sexual Magic Agreement(Which adds an extra 7.5k)
You can also skip the aid shrine and buy it in round 1 of chapter 5 instead(It becomes locked after yhilin reaches final state which happens midway through round 1 of chapter 4 if you've been doing well so it has to be bought round 1 or not at all, it gives better hidden scores if bought chapter 5 and only costs like 25k ProN) This frees up 25% discretionary funds which is usually 10k in value in this scenario.
You earn an extra 75k in profits immediately(Although your net gain is only 25k because you don't get 50k less in discounts, but that would only matter once we finally buy denmiel archives) from how great gasm falls trade is compared to archives and mercenaries, and don't have to worry about denmiel archives until round 3 letting you invest the 100k it costs post war in other investments early on. It's quite a lot of extra ProN for you to work with rounds 1 and 2. It really helps if you're planning to open the ruins before the war.
But you'll still do pretty solid buying denmiel archives and mercenaries office there instead, since you're ahead of the average that Sierra Lee expects. You could probably swing aramite supplier that way too if you want(You lose 30k(20k for Aramite Supplier +10k from lost yhilini supplier discount) buying it, and earn an extra 20k buying it(+30k from aramite supplier-10k from lost yhilini supplier income) by the end of the third arclent war, putting you 10k behind not buying it, you'll be 5k behind not buying it round 1 of chapter 5, and it'll break even round 2 of chapter 5, unless that 5k round 1 costs you a good investment).
There's also the imperfect battle of yhilin routes but those are quite a bit of discussion and deviation from your route and not everyone agrees with my stance on those routes being optimal, so I'll save it unless you want to get into those.