My JY tours have been in USA, so I can only relate to getting the best experience of those. On touring holidays, no more than 24 in my view. On each coach, the TM requires a double seat, another double is used for water/Admin bits/leaflets. The rear seat is rarely comfortable. If someone is “under the weather” they need space too. Many of the hotels appear to, , in fact did, struggle with the higher numbers, as did fellow guests. T.