Not to mention, they were on completely different systems. Vendel was in Dagobah, and Blaine and Zir Go were at Jaku. 
This doesn’t even take into account that [url=https://starwars.fandom.com/wiki/Hyperspace_tracker]Hyperspace tracking[/url] hadn’t been invented yet, so he wouldn’t even know where to go until they drop out of Hyperspace, at which point their location would be transmitted to him.