One of the reasons Hearn gets stick is because if hes confident in a negotiation he'll say so publicly and give an estimated time-line.
You're also forgetting that he'll want to approach the WBA and WBO and see if they want to sanction the fight..he wont really want just Joshuas IBF belt on the line against wlad, he'll wana try his best to have something else on the line too.
Someone mentioned on here that the hold up is the TV rights. That Joshua is with Showtime and Wlad has a HBO deal.
If true then that is a huge roadblock. It's not like Floyd v Manny where the fight is huge so everyone has to be willing to concede a bit because they will still make huge money.