Water is what cools your engine. Antifreeze is added to prevent water from freezing.
You have it backwards.
We use 50-50 to get the best of both. 50-50 will give you approximatly -35 C freezing point.
And of course the antifreeze has anti-corrosion chemicals to keep the metals from reacting to water.
As for pouring in antifreeze first…?
Wierd method. If you pour in 4 L antifreeze then only pour 1 L water, then the mixture becomes 75-25. That will give you terrible cooling properties.