[bbz]

Wouldnt changing that change the whole consept of the game. It is going to make it even more complicated. Instead of planning how to reach some research target now you'd have to plan how to buff your units by buying more than 1-2 commanders early on.And that time would have been used to get mages. So I feel(I could be wrong) but if commanders start giving bonuses, then all the races that rely on magic will be severely hurt since they cannot cope with some nations armies without magic and the need to get the commanders to buff the troops to be competative(even though a bit on the loosing side since that races with good magic dont generally have good starting armies and good recruitable troops) with the nations that will do so.It will make their research even slower thus taking them out of the game if they choose to use commanders. If they don't then the opposing armies(imagine vans or sth similar) will have better troops and better buffs(coming from the commanders) and thus completely steamroll them.
It is a good Idea but I reckon it will have a huge impact on the ballance of the game and then many more things will need to be changed. I am one of the people who supports the moto "if it's not broken don't fix it".
edit: But yea having a mod around that idea wouldnt be too bad.(and it always can be playtested to see how it works out at the end)