Given that Viserys had to flee Westeros at the age of eight and then spend much of his adult life travelling the Free Cities where he had few allies, little to no wealth at his disposal, and no army or power base to help him make his ambitions come true. All the while the Iron Throne was firmly in the grasp of the Baratheons. What prospects did he actually have in regaining his family’s throne that didn’t involve marrying his sister off to the Dothraki?