From the number of vocabulary point of view, JLPT is easy compared to Kanken, with 10 000 vocabs, you can absolutely demolish the JLPT N1, with the same amount of vocabulary, you won't even be able to pass Kanken 5 or 4. They are designed for two difference audience, JLPT is for Japanese as second language, while Kanken is for native, every small percentage of native Japanese is able to pass Kanken 2, let alone a 外人.
I don't know how much Kanken will help you in finding a job in Japan, maybe other members living in Japan will help you out on that, but passing Kanken 2 will definitely help you stand out from the crowd.
Apart from Kanken and BJT, I don't think if there is other standardized Japanese tests out there you can take.