Sherman yes, probably at the college level again. Its worth noting that he was a finalist for the Bucs job 2 years ago. While his time here wasnt great, i dont think he did enough to "poison the well" when it comes to future opportunities.
Ireland? Doubtful. At least in any meaningful job. He might eventually get another chance as a scout, but only for a team with a completely entrenched structure, such as the Cowboys. Ireland led the league in grievances against a team, publicly betrayed his coaches, wasnt well regarded when it comes to actually competency, and had a hissy fit on his way out the door.
Very few teams are going to trust him. Look at all the trouble Hue Jackson(who was well regarded when it comes to coaching) has had getting opportunities after making his power grab in Oakland. Hes now moving back into an offensive coordinator position, but that took years of working his way up the ranks again. And he was only able to do it in a place where there is no room for him to play games: the Bengals(where he spent a chunk of his career). If Jerry Jones doesnt want Ireland back, i wouldnt have any reasonable expectation on him working in the league again. And i dont think he will ever get into a position of actual authority.