This depends on three things:
Your servants and their batteries
How many farmers do you need.
1: If your playstyle consists of needing/wanting to use multiple servants that require 80% starting charge to use their np right of the bat, then you’re going to want to keep them separate. If your style consists of one singular super strong looper, then fuse them.
2: For example. If you have say an Arash as your W1 clearer, then a mlb imaginary element is fine, BUT, if you dont bother to level up his np battery due to whatever reason, then on level 1 for his battery, a k-scope is needed. If your servant does not have a 30% battery, then a k-scope is required if they have a 20% battery.
3: This one is tricky. If you use plugsuit, and you use multiple servants as farmers, then you’re going to want to keep them separate. For example, if you were to use, Arash, Mordred, and a strong support farmer with access to a mlb k-scope or already fully charged np, then you would need separate k-scopes, unless you have two mlb imaginary elements.
Another example. Take my current setup for general farming which is Arash with a 50% charger and an additional 20%. The extra 20% charger is due to my support Arjuna Alter already possessing a 30% battery along a mlb k-scope for the first np. Then I use the 50% charger, AA’s own battery, and the extra 20% charger for the third np.