RUAG was losing money in the US to start with, they never had very good sales.
The changing of management hands, the fact they bet on Hillary winning and then looking at the Trump Slump, it's easy to see how they messed up. In the suit it talks about the Swiss Gov not wanting to not be associated to Civilian US sales, that is another layer to this drama, they want to stop all civilian sales and the outside management teams were looking to purchase that side of things. Prime did not want a shitty buyout deal so the management team is looking to remove them instead.
Plus think about it, Norma and Prime are identical, Prime is popular here if you move them out of the way, you can start Marketing Norma to fill the gap. So in their mind why not control all of it vs just have it paid for as a subcontractor.