Might I ask how you define a galleon, I've rarely come across the term in relation to the medieval period. Are you thinking of the early modern period?

I haven't been able to find anything of use, although a more thorough reading of Susan Rose's Medieval Naval Warfare, 1000-1500, (London, 2002), might do. I haven't got access to a copy of The Navy of the Lancastrian Kings, (1982) which might be more specific.

There are a few references to numbers in MNW, eg. p.92:

In March 1471, however, Edward left Flushing with 36 ships and about 2000 men and once ashore at Ravenspur by guile and good luck recovered his Crown.

But there isn't sufficient information, in my opinion, to work out whether this was equally balanced, or what number of these 2,000 were crew or passengers. You might have more joy, or find something of use.

This is another passage (p.19-20), on victuals, which be of interest:

In 1385 biscuit, usually at the rate of two casks per vessel, was distributed to the masters of 53 ships at Sluys by the quarter-master of the fleet. At the beginning of the sixteenth century Phillipe de Cleves advised that a more elaborate scale of rations should be provided. A thousand people for one month should receive as well as the ubiquitous biscuit large quantities of cider and wine, 4 lbs of beef per person per week, 8 lbs of bacon per person every 18 days, 4 lbs of cheese for fast days (12 in this case) and also butter on a similar scale. Dried peas and beans should also be provided along with 500 lbs of rice to make soup. Salt fish, (herrings, ‘mollue’, and shrimps) would be needed for fast days as well as quantities of salt, vinegar, mustard, onions, and garlic. The list finishes with the note that sheep, capons, pullets and other foodstuffs can also be provided by the crew themselves either for their own consumption or for the sick and injured.

Victualling on this scale was never attempted either by the Venetians or by English shipmasters. The ration scale for galleymen in 1428, said to have been in existence ‘ab anticho’ was 18 ounces of biscotti or 24 ounces of fresh bread per day. The other victuals provided were wine, cheese and beans. English ships in the king’s service in the early fifteenth century were victualled with bread and flour, beef, mutton and salt meat, salt and fresh fish, beer and wine. In 1440, Thomas Gylle, from Dartmouth, who was commissioned by the king to undertake a voyage to Gascony in his ship the Christopher accounted to the Crown for the purchase of flour, beer (54 pipes for a crew of 93), 27 beef carcasses, salt fish including ling, hake and ‘chelyng’ some extra salt and four bushels of oatmeal. Even if these provisions would provide only a very monotonous and not very nutritious diet, assembling them for a large fleet could be a great strain on the food supply in the vicinity of a port. The possibility of a naval expedition feeding itself ‘off the country’ in the manner of an invading army clearly did not often exist, something which added to the expense and difficulty of conducting war at sea.

Galleons were developed in the 16th century. Do you mean a galley? There was no unified style or definition for a medieval galley though, so the answer is going to vary from ship to ship, galley being a sort of catch-all term for a Mediterranean oared ship. Furthermore, the same ship could have different numbers of men on each oar. Also, are you including the soldiers on the galley as part of the crew?