User blog comment:Pomi098/Favorite Sun and Moon starter Poll/@comment-26618197-20160903133850

I usually go with water type starters, usually they hit hard and hit fast, and unlike it the age of the fire/fighting starter Litten is likely a fire/dark type, assuming that Litten is a fire/dark type in one of his evolutions and assuming that Poplio will always be a pure water type here's their strengths and weaknesses

Rowlett:

4X weakness to ice

2X weakness to flying, poison, rock, and fire

1/2 resistant to fighting and water

1/4 resistant to grass

Is not effected by ground

Litten (assuming he'll be fire dark):

2X weakness against fighting, ground, rock, and water

1/2 resistant to ghost, steel, fire, grass, ice, dark

Is not affected by psychic types

Since we don't know Poplio's confirmed evolution he'll remain a pure water type for this listing

Poplio:

2X weak to electric and grass

1/2 resistant to steel, fire, water, ice

So in number of weaknesses the ranking is Poplio, Litten, Rowlet

In number of resistances it's a tie for now between Rowlet and Poplio and Litten comes in 3rd...