As I said the planet will be bigger than the sun itself?
With monsters and gods that could demolish continents bigger than the earth. And possibly the whole planets split mountains with their bare hands controlling all the aspects of life and death, creation and destruction, time and space of course people like these who could control time space life death would be very rare on the level of god's.
And the smallest kingdoms would be just a little more bigger than Algeria and the planet 's human population alone would cross 50 billion. And still they are not dominant species.
So it won't be a small summoning list. It's not possible as on every level mc gets a summoning token. And of course with every level he climbed it was harder to climb, the next level required a lot of XP which also meant starting levels would be easier. So more summons to start with…
Now on the topic of choice if you choose a normal summoning system then Waifu's were still going to be the dominant once.
With males like Thor of Gow, Grap of one piece, Zombieman of OPM, Ogre of Warhammer 40K, etc
With females like Esdeath, Leone, Widowmaker, Tokisaki Kurumi, Kuriyama Mirai, Kiryuuin Satsuki, Queen Maeve, Lucy, Ezra Scarlet, Mirko, Misaka Mikoto, Ais Wallenstein and many more.
So only Strong Waifu's who could fight.
So choices won't change no matter what summoning system or waifu summoning system, what would change would be there won't be any male summon but the story would still have many males.