No way to be sure without seeing the paperwork but that word 'owner' is a strong tell that this is stock, not just a profit share (note the direction of the arrow, but even if it is just a profit share that profit share still is a function of the stock held by the entity and if that stock loses its value because the underlying company is destroyed then so do the profits). So with that as a base I hope you can understand why I think the fiduciary duties of the board extend to the employees affected by their decisions because it directly impacts the value of the stock held in that company to which they - and the other investors mentioned - hold (possibly indirect) title.

These arrangements are pretty common in fact (though not the non-profit bit, just the separate entity for smaller shareholders and investors), and the other stand out is that they label the other party in there as 'investors', not 'donors' or some other party to which you are not required to answer.

So to me it is far from clear cut that they only have the mission of the non profit to guide themselves by and they set themselves up for that by wanting too much control (also over all of the other entities). Control is good when you want to have your way, but too many hats on your head with too many different labels can constrain you or open you up to liability or conflicts of interest. It's one of the reasons why I try to limit my engagement with various companies to a single role.