Unfortunately, generics can vary wildly in efficacy & quality. As @Aradina pointed out, sometimes the encapsulation is different (e.g. extended release coating vs. standard release), but also the form of the drug can differ (e.g. capsule, tablet, softgel, chewable, etc), chemical by-products from different manufacturing techniques may be present in different amounts, and different manufacturing processes can also yield different chiral enantiomer ratios in the end product.
The “same” drug from different manufacturers may vary in effectiveness / side-effects, and brand-name drugs aren’t always the best formulations for most patients.
Communication Workers of America is probably the closest to what you’re looking for. You’re definitely better off working with an established union instead of trying to build one from scratch, they have a lot of valuable experience and resources that you’ll need to pull off a unionization attempt. If you reach out directly to CWA, or any other union, they’ll work with you to help organize your workplace.
If you are serious about unionizing: first, see if you can get a few of your coworkers on-board by talking to them outside of work. Do this in-person or on voice calls that aren’t recorded, it’s crucial to keep the company unaware as long as possible so they have less time and ability to oppose you.