The default mashing profiles start with a water/grain ratio of 1.25 gts/lb (approx 2.6 liters/kg), which is what you got. Of course you can change it to anything you want, as Bob pointed out. That number is considered a "sweet spot" for conventional mashing. As I understand it, this ratio gives good efficiency and also a well-behaved grain bed for lautering. For BIAB the water to grain ratio can be as high as 3 qts/lb (> 6 l/kg) with no ill effects, since the grain bed doesn't matter. If you measured accurately, then the quantities you listed should not have produced an overly thick mash. Are you adding the water to the grain or vice-versa? I find it much easier to get a good mixture if I heat the water first, then add the grains slowly while stirring and poking to avoid any dough balls.
--GF
P.S. I don't think there is a budget on posting. As long as you continue to be polite and courteous, post as much as you like.