I love to have an abundance of manufactories. I'm currently in Amuni and I have 7 maxed planks (plus one level 19 that's tucked into a corner simply because I didn't have enough teleports after the last FA, and I've just ignored it.) I have 6 silk and 4 dust, along with 4 for sentient goods. Since I cater most of the spire (for fun, mostly, since I love developing the strategy of the negotiations) I need those goods.
I also fight, hence the reason for the Dwarven bulwark plus 4 maxed armories. I have to admit I'm always fighting for space, but that's okay. Everyone has their own style of play, and where many choose one path and stick to it, I like doing both fighting and negotiating. I mostly fight tourneys, since the negotiations are just basically caving there. In the spire they are more fun.
Gladiola, whatever works for you is what works for you. Before I had my Prosperity Towers and acquired a few magic workshops from the spire, I used to have eight maxed workshops out. Now, I only have 6 magic ones, so that saved some space. If you are in a fellowship where you can acquire blueprints for upgrades, then as soon as you can do the spire, make it a priority to get some magic workshops and residences. That will save you so much space for those multiple planks. Frankly, I find Tier one goods the easiest to trade in the trader, even cross tier trades. No one seems to mind when you sell 10K planks and ask for anything else on a 2 or 3 star trade. (planks is my boost, too) The strategy always worked for me.