The current bonus is already much stronger than Will to Fight, as 20% more pop means 20% bigger armies, which means your army deals ~20% more damage and has ~20% more hp. And you also get the resource trickle. 50% more pop is ludicrous.

I think it would be great if wonders could be buffed because currently the amount of resources it costs to get a simple 20% upgrade to population is just not worth it, perhaps increasing damage, reducing cost of champions or units in general or simply increase the population number by a bit more than 20%, maybe 30-40 maybe even 50% so then it's actually worth getting?

For the avoidance of doubt, lets not respond to threads from new members seeking help in C&E with Kyle Mills / Murali jokes. Unfortunately I dont have a whole lot to contribute on the actual topic.

@Stockfish  

x3 was known to work in some a26 com mod version. Champ cavs where countered more like one would expect by spears. If this is too much early on against cs melee cavs, we could instead add a tech with this +50% (+x0.5) dps against cav bonus? Melee cavs are quite strong early game anyways so could be either way.

This is exactly what we want - a counter unit. Even at 5x bonus, the spearman would still take some heavy damage because of the insane damage values from the champ cav. it would make the champion cav sufficiently weak in a fight against other unit types, so the op problem is solved. If all you can do is have a lot of champions running around but not take fights, then players will be discouraged from champ spam.    but this is still not as good as just moving them to a fort or a special building only. 

That would push us even further into playing "keep away" from the spearmen, which is pretty easy, but when you are forced to take a fight against spears, they will just get absolutely melted. A 5x counter might actually win with a numerical disadvantage for spearmen since they would rank up incredibly fast. edit: spears can win 25 vs 20 champ spearcav w/full techs. No, I'm thinking bigger picture speed balancing, but it will be near the bottom of my list.