Absolutely, Rodon has risk. The price for any top-end player is always higher, so higher risk. Rodon and Smyly and Senga all have risk that they won't be good or will get hurt. Inevitable that the better a pitcher is and the more he costs, the greater the risk in case you get nothing out of the money invested.
Boras pretty much always claims he has some "secret" bidder, so Hoyer may become that guy, who knows? But most likely Hoyer isn't pursuing the most elite guy on the pitching market. Sharma used "monitor" for Senga, not "pursue". In Rodon's case, I imagine Hoyer might at best be "monitoring", not "pursuing".
A guy of Rodon's caliber can get a zillion from any contending club that he'd like to sign with. For him to prefer the Cubs to the contenders, Hoyer would need to offer Zillion+20%. Why would Rodon otherwise sign with the Cubs if they don't offer 20% more than the powerhouse teams? Rodon will be risky and expensive at the zillion that he'll get from the contenders market; I'm doubtful that Hoyer wants to not only meet the market zillion plus also supersede it by an additional 20%.
If I'm wrong, I'll be pleasantly surprised.