They're RTB's private venture : he commissioned the figures from Paul Hicks and he is selling them to individual customers to finance their production, but he didn't set up a company for that purpose - same principle as Emil Horky's Bohemian Troops.
Paul's Poles (sorry, couldn't resist...) are meant to be compatible with Perry and Foundry, though bear in mind that the Perry twins sculpted Napoleonic French for Foundry over a period of nine years and that their later sculpts are much taller than the original French troops in full dress released in the early 1990's). These Poles are taller than the Foundry Austrians and Prussians (which are rather small) but are a perfect match for the Foundry Russians.
They are also about the same height as Front Rank, but they're more slender, less bulky and generally better proportioned.