Well, that's all you need.
Then you have to edit the file 'data\ini\default\water.ini' and the files in the directory 'data\ini\default\balance_SEE\'. Look for the term BUILDTIME. Almost every unit and structure has one of those entries. Which ones control which unit is often apparent, like this (for a goblin warrior horde):
#define M_GOBLIN_FIGHTER_BUILDTIME 60 // in seconds
To adjust the buildtimes, you'd have to change ALL of those by hand.
If you are somewhat proficient in modding (which i guess you aren't), you could also make every map spawn an object with an aura effect (large enough to encompass the whole map) which would provide every structure an AttributeModifier (SPEED 200% for example) to get over that.
Axed Head and A.I. Coder for S.E.E. and ... stuff
".. coding is basically boring. What's fun is finding out how things work, take them apart and then put them together in ways that were not intended nor even conceived."