I've been considering a simple, mod-based solution to the pioneer spam problem, which consists of 3 key moves:

1. Make explorers able to build outposts, and

2. Make pioneers cost a significant (100+?) amount of population, which is subtracted from the cities which produce them

3. Make cities begin with 50 population

Obviously the balancing of pioneer cost and city population will have to be fine-tuned, but my thinking is that this change will make pioneers relatively more costly at the beginning of the game and for smaller cities (when city growth is important) while keeping them relatively cheaper for larger cities (which have a lot of population, and don't need the growth)

Does this seem like a good idea? Do people see any issues I haven't thought of? I can try and mod this for Beta 5 with the help of the experts (seanw, heavenfall) if people like the concept...