Distance of GK board from screed floor on the upper floor

Hello, I urgently need advice. The site manager says soundproofing. Yes, the distance can be somewhat smaller but okay. I say no, it seems too big to me. It concerns drywall panels to the floor screed. In the upper floor, the sloping roof

Feel like I have 1cm of space.

And how big is the distance?

That fits so far. Missing as an example are impact sound insulation and laminate. And a baseboard still needs to go all around...

Distance 3.4 cm

And how large is the distance?

3.4 cm