>>29339388Maxie was scientific genius who worked off of logic. Wanting deeply to expand land and increase exploration and expansion for humans he searched down the being that created the continents. Having calculated what he thought would occur he was able to deduce that Primal Groudon's awakening would cause a bit of choas but would lead to a better, more advance world and he could achieve his goal. He never expected a nearly worldwide apocalyptic drought.
Archie was probably just a guy that liked the sea who worked purely off of passion. When he saw the mistreatment of the ocean and it's Pokemon by humans he was furious. Driven by his love of sea life he tracked down the being who once ruled the ocean in an effort to punish the greedy humans of the land who tainted his beloved ocean. He thought that the beast could be tamed and controlled to take a bit of land away from those who didn't deserve it and given to the ocean dwellers that he thought needed it most in the form of the water that submerged it. He never expected a nearly worldwide apocalyptic flood.
Tl;Dr: Maxie was a man of science, Archie was a man of impulse. Both of them thought they knew what they were doing, neither of them actually did.