They had little to no offense. They had a fairly decent offense. Nothing spectacular, but nothing terrible either. They struggled to move the ball against Alabama and Florida, but they also put up over 30 points on 7 different occasions. They were 46th in passing yards, 54th in rushing yards, and 65th in points for. Not great, but efficient to a degree. That being said, I do agree with you when you say the offense won't be any better. They don't have a QB that has ever taken a D1 snap. Their most experienced running back Tauren Poole really doesn't have that much experience, and they're pretty slim at receiver and in the O-line. I say 6 wins is the BEST case scenario, but I wouldn't be surprised to see them only win 4 or 5.
I don't think Dooley is a band-aid coach though. He's not the high-profile guy they're used to having, but he's from a good pedigree when it comes to coaching, and he's an excellent recruiter. I believe he was the recruiting coordinator at LSU when they won the national title with Saban at the helm. Tennessee fans just need to give it some time. He'll have them competing again in due time.