MAJOR CALLS

I dont know if anyone else is experiencing this but the major calls (building collapse, industrial fire, high rise fire, gas station fire) sometimes get out of hand. too many of them come at once, and it is outside of reason to get 10 moblie command units when i have 30-40 stations. can we get the happenstance of the major calls reduced abit please? and it wont interfere with credits because there will be more units available to handle small calls quicker, instead of big calls slower.