Above: 10mm Conquistador Arquebusiers from Obelisk Miniatures http://www.obeliskminiatures.com/ These are suitable for the Italian Wars.
An early, somewhat thorny problem is the ratio of espingarderos (hand-gunners and arquebusiers) to ballesteros (crossbowmen) in the Spanish expeditionary armies. Thorny because, while most of the time the Spanish tell us how many arquebusiers were part of a particular force, the crossbowmen were counted among the pikemen.
Working from several standard sources, I was able to determine the following ratios:
The ratio of firearms to crossbows in an Imperial force organized to fight the Hussites in 1431 was 1:1
The Emperor Maximilian eliminated the crossbow in the Imperial armies in 1507.
The ratio of espingarderos to ballesteros in some later armies of the Spanish Reconquest
1483 1:6 (handguns:crossbows)
This data is quite interesting when compared to the ratio in Italy a few years later. In the space of a decade, the ratio is reversed. These were the first Spanish expeditionary armies organized on the new model.