Look at these sentences:
(1)He lost to a better player. He won in every other way one can imagine.
(2)You/one can get very nasty skin diseases from bathing in dirty water.
It can be seen that both the italicized expressions start with the general subject you/one. Can I replace the "can"s in (1) and (2) with "could"s to make them sound more hypothetical/less assertive?