Euan Aitken is not who I would class as a 'very good defender'.
In his time in the centres, he failed to tackle above 90% efficiency. But what was worse and what doesn't get highlighted here is his reads out wide. They have been woeful for a very long time.
Credit to him, since moving into the second row his tackle efficiency has risen above 90% now, but I would still have major concerns about his decision making on an edge. Unless he is a cheapy, which I highly doubt would be the case, he isn't worth pursuing imo.
Especially when he have a cheaper, and better, version in Garner currently in the club this year and who is yet to be extended.