Payment plan okay - 13% after the floor slab?

Our payment plan is as follows: 15% after building notification and completion of the foundation slab 30% after erecting the roof frame 13% after installation of the windows 22% after completion of the screed. 15% upon completion of the contractual construction services (except for minor remaining work) and acceptance 5% upon defect-free handover ([Schlüsselübergabe]) This allows me to sleep well, and before each payment, we will have a building expert check whether everything is in order and then pay or, if necessary, report defects.

Our payment schedule is as follows: 15% after construction notification and completion of the base slab 30% after erecting the roof truss 13% after installation of the windows 22% after completion of the screed. 15% upon completion of the contractual construction services (except for minor remaining work) and acceptance 5% upon defect-free condition and handover ([Schlüsselübergabe]) This way I can sleep well and before each payment we will have a construction expert check if everything is in order and then pay or possibly report defects.

Our payment plan:

25 % completion of [UG]
15 % completion of [EG-Decke]
12 % completion of roofing work
20 % completion of interior plastering
10 % completion of tiling work
4 % after acceptance
6 % after exterior plastering
5 % after exterior landscaping
3 % after rectification of defects identified during acceptance

These payment plans are really something. They really don't have much to do with the actual costs. It all seems pretty random.