For the sake of discussion, would a 1GH or 2GH miner even be able to find a block on ckpool against all the few hundred GH and TH there?
It is not 'against' - there is no competition.
Everyone is simply rolling their own 40,640,955,017 sided dice.
Each time anyone rolls a 40,640,955,017 they win a prize

... and more Gigahashes simply means you get to throw the dice faster (more throws per second)...