The standard here is to use a battery bank. You would need a blocking diode on each windgenerator for a 12 volt system ( or one diode if a 24 volt system)to keep them from motoring when the wind is lower than cut-in speed.
If you try doing as you propose, using no batteries, the inverter will shut down for low voltage as the mills produce less than you need power wise. Then when the wind picks up, the mills will have no over speed control. Just a thought... Gary D.