Yeast to sourdough advice

I have a pretty fail proof yeasted sandwich loaf made with poolish and yeast and want to switch to sourdough. Here’s the formula 

POOLISH (made night before)

246g flour

246g water

1g fresh yeast

Main dough

Poolish

574g flour

182 g water 

9g fresh yeast

17g salt 

53g eggs

38g butter 

119g cream cheese 

My question is if I make poolish into levain can I just skip the yeast in the main dough and still be able to finish the bake in the same day because of time restrictions and how to determine how much starter to use to build the levain. Any advice appreciated 

Thanks

Dom