You're welcome!
A french court would disagree with you - the German process you described is impossible in france. once an employee has finished their trial period, only gross misbehaviour or an official economic redundancy plan can get rid of them...
But it's not like in the US where you just declare this, and then fire them. It works like in many union shops in the US. You need to document that poor performance, show missed deadlines, show that you attempted to train and accommodate them, give them a few months of heads up to adjust, and then you can proceed with dismissal.
Just think of France as an all-hands union shop.
Anecdotally, I've heard about companies with these, which got that way by getting sued over and over again for wrongful termination. Now they are scared to even discipline employees engaged in sub-extremely-egregious behavior.
Like one story I heard was, "As long as they spend more time working than looking at porn, let's just let it be."
My 2 cents on this: Your company gets this way with poor leadership. Terminations without your i's dotted and t's crossed, and also an unwillingness to take some things on the chin for a broader view of how things are going to go.
Americans will tell me how onerous this is and yet they somehow managed to screw it up anyway because I constantly read on the internet about "unfireable" employees which is a ridiculous concept. Even hiring quotas for large corporation's and government funded institutions (universities for example) don't matter when making firing decisions, the point is to let people with other backgrounds into the door, not keep them locked in.