He was also a powerful figure in the United Self-Defense Forces of Colombia (AUC), an umbrella organization bringing together right-wing paramilitary groups from all over the country.
He was well known for being a ruthless fighter against guerrilla groups, and for being able to evict these rebel groups and take control of their territories.
The Centaurs bloc was one of the largest and powerful groups within the AUC, and were very organized to the point that they even had a running web page that is no longer in service (www.bloquecentauros.org).
Arroyave was one of the AUC's team of negotiators when talks began with the government on demobilizing the paramilitary organizations which had proliferated over the past few decades.
These paramilitary organizations were created first to fight against the left-wing guerrilla armies which controlled large parts of rural Colombia since the 1960s.
Arroyave was very close to the Castaño family, founders of different paramilitary organizations, and he also had control over the Capital bloc ("Bloque Capital") which controlled the paramilitary militia in Bogotá.