Actually, the Spaniards fielded 15,000 at the Battle of Garigliano (1503) while France had 23,000 in the same battle. And Spain's Army of Flanders numbered 20,000 in 1567. While logistics were a limiting factor for armies on campaign, France and Spain were capable of fielding large armies. And by 1589, the Dutch had a paid, professional army of their own under William Louis and Maurice. IMO, trying to compare the Dutch in the Eighty Years' War to rebellions is faulty...the Dutch held territory, had a civil government, and had an organized military. Rebellions in EU4 don't start holding land, don't have a civil government, and aren't professional troops. And EU4-type rebellions don't historically have a good track record.