I think that the keen mercs don't show up right away. While Kerns and Welsh spears are common as dirt on the British isles. Gallowglaich and Welsh longbows are very rare. Swiss and Flemish pikes are more common. In fact the rebels of Bruges and Antwerp have Flemish pikes in them. Also some really good mercs need an event to show up. Like Free company longbows and men-at-arms, and merc arqubuiers. Also in the east neat mercs are more common. Bulgar brigands, Slav archers and spearmen, in the balkans. Armenian archers and cavalry, Cuman horse, Alan cavalry in Asia minor. Sudanese swordsmen in Egypt, Catalan mercs in Iberia.