I work for a company in Germany with many group companies across the EU. Often projects have to be conducted in one of these group companies in another country, so I have been asked to resign from my current position and then to apply to one of these group companies to work for several months on a project, and to continue doing this multiple times moving forward.
I believe the company is working in good faith, and while they have the ability to delegate me to one of these organizations rather than having me resign and then join the group companies they have told me this is a better strategic choice. While I can refuse, the company is strongly pushing for me being reassigned in this way.
I am not worried about my CV, as all these companies are part of the same group and can count as a single employer even if the specific companies are different, but I want to make sure there aren't any hidden drawbacks from changing positions this way.
What personal/bureaucratic consequences can there be for changing companies and countries several times over the course of a few years?