Alexander,
I will try to answer to your question.

I guess in the beginning Germany was better prepared and the German planes were best.
According to prewar theory the bombers were the decisive weapons and so most of the development was put in those. Furthermore there was some synergy from civil planes. Early 30ies most bombers were more modern and therefore faster than fighters. Therefore most people thought that there was no need for fighters at all, only to protect some objects, maybe.

Germany was lucky because despite of this doctrine Messerschmidt developed the Me109, which was outstanding then (please note that it already fought in the Spanish civil war!!).
The German bombers were made for tactical missions and ground support. Germany realized that it did not have enough resources sp it made too decisions: no resources to strategic bombers; all bombers had to have the ability to dive.
The Stuka was anoutstanding plane in the beginning of the great war. There were few interceptors and weak air defence. So they could dive straight into the target and had an excellent effeciency.
The two engine bombers were very fast (due to the doctrine that they had to be faster than fighters) and had only weak weapons for selfdefense.