Well you can to an extent by team.
League Menu --> League History Index
Click a league from whatever year you want to look at,
Click the team you want to look at.
It now shows you team batting, pitching and fielding stats by position.
It also shows the ages of the players and at the bottom the average age.
Wold love to be able to find that easier but it is there. Might be easier to copy info into Excel and calculate the average age but it is there in a form.
Edit: SirMichael types quicker than I
