In his blog post, the student argued that besides the overconfidence of the German, the strength of the Allies' code itself contributed to the breaking of the Enigma code. I thought this was a very interesting viewpoint and never considered this before. The surprising usage of the Navajo language as military encryption proved to be unbreakable, thus allowing the Allies more time and resources allocated solely on cryptography.
The importance of resource usage and allocation is certainly important in the cryptography war. German's sloppy and careless usage of the machine played a role in the Allies' success. The machine workers made a few mistakes that wouldn't have been made if they had a certain level of understanding on the working mechanisms behind the Enigma machine. For instance, by never repeating letters in the daily scrambler settings, they actually eliminated repetitions for the Allies' cryptanalysists. On the other hand, Allies were especially protective of their codes, with only Navajo speakers controlling the content of the messages.
In addition, as the Allies had more time and resource available to focus on code-breaking, they were able to allocate the accurate resources. As they dealt with the Enigma machine, the former strategy of recruiting linguists was abandoned. They were able to focus their resources on scientists and mathematicians, and thus eventually beating the machine with another machine.