Of course gold and food would be useful. But most people would rather march 80 soldiers down than send 300 gold every other week. Marching troops is exciting. Sending gold is boring. And giving it away? Meh... there's no excitement for most people in bankrolling someone else's war.
Do both?
If you can send troops and fight, sure, totally do it. However, last time everyone came, distance from the realm seemed to K.O. your armies.
You did send small forces to good effect, though.
