I would suggest the following approach:

As discussed in our call a few weeks ago, some of the parts of your list below are optional, right? So I wanted to ask if the following would make sense:

 

    Specialist Hrs Manager Hrs
1 1. Take the English master keywords and translate them with e.g. Google translate (or another tool) to Chinese 4 1
2 Insert the Chinese keyword suggestions into CN keyword planner tool in order to complete the research with keyword suggestions, and stats like competition, search volume, etc. 8 0.5
3 Plausibility Check: Go through the final list of keywords and check for plausibility, delete keywords that are not relevant and mark the best suggestions as prio keywords 4 1
4 Quick Sort the Chinese keywords into different category and map them to the predefined categories in Tab 2 “SEO relevant Sitemap & KWS” (as this sitemap structure is fix and can’t be changed!) 4 1
5 Translate the Chinese keywords to an English Referral version for the clients to review 4 1