[Saxon]

Based on the various suggestions, I have tried some games with easy research and lots of gems. It seems that was all that I needed to do! Easy research takes the research points back to the Dom II levels, if my memory is working, which is great.

As for the effect on large multiplayer games, I can not say. I would be interested to know the proportion of the large sales of the game that end up playing multiplayer. I suspect (on the basis of no evidence!) that the large majority of people play single player.