What will happen if two different size generators are paralleled?
As AlexVS said, the two generators will short-circuit. This might damage the generator of less power.
When the generators are in synchronicity, all power is delivered to the consumer (resistor R on the picture). The resistor is consuming maximum generated power of  2.2W.

If one generator is out of synchronisity, one part of generated power will remain circulating between two generators, depending how much the generator is out of synchonisity. This might damage the smaller generator, increases the heat of both generators and consumer is not getting all the available power. On the picture below, the generator U2 is 40° out of synchonisity.

Source: falstad.com