Hazard is a transfer that failed miserably, because Hazard was brought in at a very high price but Hazard did not have any contribution to Real Madrid. So, even if Joselu doesn't really contribute well, it won't be a problem because Joselu is an old player anyway. So yes, we cannot expect the same performance and contribution between Benzema and Joselu, because of course they have different skills and power. But anyway, at least Real Madrid have a good movement to be able to regenerate the team for the long term, because the young players that Real Madrid currently have are considered to have great potential and quality from time to time.
Hazard wasn't really a "bad" transfer but more about how he just disappointed. He was an amazing player when he played in Chelsea and that made Real think that maybe he will play like that for them too, there is nothing wrong with that, how could you know that he would be this bad?
I mean they are buying players all the time, just this season they spent like 150+ million euros so far, with player salaries and sign bonuses that's like 200 million at least, and how would you ever know they won't be terrible? You possibly couldn't know that. This is why Hazard was definitely an unlucky transfer, but I wouldn't say that it was a bad one, there is a big difference. The difference is that they got smarter about it and been doing amazing transfers for a while.