Re: Where's the substance?
It does matter who they are because there are rules about nationality. The Trump campaign sent donation requests to UK citizens, many of whom replied by advising that their campaign management should check the law about receiving donations from foreigners. It hit the (non-Breitbarf) news big time. Likewise the leave campaign should have received a severe spanking for accepting goods from Cambridge Analytica without declaring it.
Voters are supposed to be able to find out who owns their politicians, and the owners are not supposed to be foreigners. Imagine the outrage if it had been discovered that Mexico had supported Trump to get jobs and cement orders for building the wall.