In the match which Rahul Dravid hit 145 against SriLanka, he was not the wicketkeeper. It was a world cup match and the wicket keeper was Nayan Mongia.
It is not justified to compare Dhoni with Rahul Dravid in this particular article. Dravid is a regular batsmen and only a standby wicketkeeper, Dhoni is a regular wicketkeeper.