Quite solid trades. I see some potential in these.

does it help defensively that much? you've put nylander at centre late in the season which isn't a good thing. sure hjalmarsson is when he's playing well is better defensively than gardiner but takes about the leafs only offence from the defence. tanev is ok to good, but he's on ltir again/still. does he really help. trading three good futures for him is certainly more than any other team would trade for tanev.
if tanev continues to ltir and he likely will be on again anyway this version of doesn't help now and it certainly not the future. probably Nashville would have no interest in jvr