No, it's to further emphasise why they're different from Ferguson.
The team certainly didn't fail while Duncan Ferguson was with us, we won the league in 93/94 and 94/95 the two seasons he was with us. I'd also argue his signing spurred Hateley, the man he was supposed to succeed, onto greater influence, Hateley was our top scorer in each of those seasons.
Duncan Ferguson is one of the great 'what might have been' of the last 50 years. He was the victim of David Murray's ego, SDM was angry that Jim McLean was reusing to sell him to Rangers. He should have bided his time, perhaps arranged a 'Gough' and got someone down south to buy him for a season then sell him to us. We were powerful enough then to do that. But instead he arranged for friendly journos to write stories about how hard done by Ferguson was and ramped the pressure on Dundee Utd until eventually they agreed a very acrimonious sale for a then British record fee. That simply put enormous pressure on Ferguson from day 1. For all his undoubted talent Ferguson was a big daft lad, and the glare of publicity and expectation that came with the move wasn't a great mix with a young man filled with confidence and bravado.
With hindsight I think Ferguson should have gone to Bayern Munich, who apparently made a bid for him after he'd terrorised the German defence in one of his few games for Scotland. What a player he could have become with the level of coaching and technical input they had. He's still have to come to us eventually, but he'd have been older, wiser and a better player.
Anyway, there are number of labels that could be justifiably put on Ferguson, but a dud most certainly isn't one I'd use.