Which grass seeds should we sow?

Good day,

we are facing the decision of which grass seeds we should sow.
We have a new building that we took over at the beginning of the year.

We have roughly shaped the garden and sown grass.
Unfortunately, we are struggling with waterlogging and, on the recommendation of the civil engineer, will have a drainage system installed that drains into the existing soakaway and allows the water to infiltrate into deeper layers (the soakaway is about 4m deep). According to the civil engineer, we have clayey soil, so the water does not drain properly without drainage.

The plot faces southwest with lots of sun but also partial shade depending on the time of day (but never full shade).

My question to you is: which grass seeds would you recommend to us?

We are looking for a lawn that can withstand dryness well in summer without needing to be watered but also has no problems with somewhat more moisture and should cope well with somewhat clayey soils.
The lawn should also look nice and green (short periods where it is not completely green are okay).
It should also be suitable for a robotic mower and low maintenance.
It should also be robust if children play on it or a dog runs around on it in the future.

Should we choose a drought-resistant lawn?
Or which grass variety would you recommend to me?

I also found grass mixtures (e.g., from Rollrasen Rudi 4 in 1). What do you think of a mixture like that, which is supposed to cover everything?

What would be your recommendation?

The egg-milk-laying wool-milk pig does not exist. The more customers like you there are, the more magic mixtures there will be, at an overpriced price, but the chance of survival from straw to straw is individual.
A lawn needs water - be clear about where your ecological thumb wants to go. Many live with it burning, but it comes back.
Others install expensive irrigation systems and ruin the groundwater level.
The really beautiful and perfect lawn needs care every day, water in drought, and fertilizer every 6 weeks. The fertilizer also needs water. With clay soil, I would reduce the demands.
South side also only says something to a limited extent, because if you have a hedge, you have a one-meter strip there that will moss over because of a lot of shade caused by the hedge.
Do it like most pragmatic people: where you sit and look, a little more care, leave the rest to nature.
Play and sports lawns can handle dogs and children. The important thing is the right approach at the beginning of the gardening season.
By the way, lawn is the plant that needs the most care in the garden. But it also brings joy.

That you always pull yourself up on the irrigation systems. Still better to plan something like that properly and water at times when the sun is only weakly shining on the earth than to set up the sprinkler at midday and let 70, 80% evaporate in the midday sun before it reaches the root...

And ecological thumb, I’m dying of laughter. Nothing is less ecological than a detached single-family house with 160m² for 3-4 people, double garage for 2 cars, 50m² paved area in front, preferably 2 diesel cars, 50m² stone terrace, pool and double rod mat fence or even better gabions or stone wall 2m high.

That you always climb up the irrigation systems. Still better to plan something like that properly and water at times when the sun is only weakly shining on the earth, than to set up the sprinkler at midday and let 70, 80% evaporate in the midday sun before it reaches the root... …

Calm down. The only one climbing up is you! Here, ways were pointed out factually, you are already so drunk again that you do not see it. Terrible, really terrible!

Does it have to be grass (playing field, etc.)? Otherwise, there are significantly easier-to-maintain plantings for heavy soils.

My beautiful lawn No. 30 should certainly be quite suitable.