Thanks for joining this thread, jaapkrijger.

Yes, you can enter different related units for a second supplier that are the exact same as your previous supplier's related units. Units are defined by the number of base they contain. For example, if your base unit is an inch, a related unit might be a foot, which is defined as containing 12 inches. Another related unit could be a yard, which is defined with 36 inches.

Related units make it possible to show quantities of the same item in different measurements. They allow you to purchase items, count them in measurements, then sell them by measurement.

I've also included a detailed resource about working with related units which may come in handy moving forward: Use single & multiple units of measure for items

If there's any additional questions, I'm just a post away. Have a great day!