Well considering a Yellow Tang requires at least a 75 gallon tank and a Kole tang around a 100 gallon conventional wisdom would say no. Although a Yellow Tang is of the Genus Zebrasoma and a Kole Tang is of the Genus Ctenochaetus. Tangs of the same Genus or that are similar in apperance will often fight, typically violently. Although these two tangs are of different Genus classifications and look totally different as well.
The question you need to ask is how large are the fish. If your Yellow Tang is one of the 1.5-2 inch juveniles I often see for sale and the Kole Tang you are looking at is one of the 2 inch juveniles than you might be ok. Tangs grow at alarmingly slow growth rates and at young ages and small sizes dont require near the room that they do when they are adults.
Just remember that eventually you will either need to upgrade to a larger tank (100 gallons +) or get rid of the Tangs. As for them living together in a 44 I think it would go for a year considering they grow very slowly. Again if your Yellow Tang is a large sub-adult (3 inches plus) or the Kole is large than it is a major no-no. If both tangs are very young and small and you do get them than I would recommend supplementing thier diet daily with Green Marine Algae soaked in a Multi-Vitamin formula since if HLLE
develops at that age it is nearly always fatal.