This was the primary time and Trump was a brand new politician. His connections were in the business world so he relied on others to suggest people to join the Trump team. Manafort was highly recommended due to his work on previous presidential campaigns.
Do you think Trump had time to go and check out who was registered under the Foreign Agent Registration Acct? Trump probably checked out Manafort's success on the campaigns he had previously worked on.
"Vladimir Putin assigned him to Trump." BS!
There is NO proof that Putin was involved in any way of Trump's campaign.