Comment 1 for bug 1422158

A rather simple solution would be to give each tribe two trainers in the starting conditions. In bug 669699, where the buildcosts of trainers have been discussed, no tribe was given additional weapons. This change would therefore re-establish the state before the change, where a player could produce trainers easily.

This would only solve the issue for the first two training sites, but that should be sufficient IMHO.