What is 'mixed' about Atkins' trade history? The Mitch White trade?
This FO clearly has a better read on their own prospects than the AA-led FO did. Sending Syndergaard instead of Sanchez is the perfect example: he misevaluated and sent the wrong guy. Allowing Musgrove to be a throw-in for Happ is another one. Atkins has made a lot of trades, and the underlying theme is that they're generally trading away surplus guys or guys who are on the precipice of losing lustre. They have a clear idea of who they want to keep and who is expendable; there seems to be less "guessing" which is generally what allows other teams to come in and scoop potentially elite talent away from you.
The worst part about AA's trades wasn't about what he gave up, it's that he turned a cheap and prospect-laden team into an old and extremely overpaid roster overnight, which gave the team little to no wiggle room. And the "stars" he was acquiring were generally all guys who were in clear decline. So he locked up all of his financial flexibility on guys like Reyes, Dickey, Tulowitzki, Buehrle, etc. which meant that when they needed to add more to fill gaps, he couldn't do it in free agency because Rogers wouldn't let him. Buehrle was at least good and provided value, but he was paid $19 mill and $20 mill in his final two seasons - he was hardly a "bargain". Reyes was a colossal mistake, and then they needed to trade even more prospects to get rid of him by turning the clock back a bit to acquire another anchor contract in Tulowitzki.
A guy like Daulton Varsho makes nothing. Even if he never bounces back with the bat (seems unlikely), at least you aren't crippling your roster by acquiring him. Same thing with Mitch White: yeah he sucked and you maybe traded a good prospect for him, but his failure doesn't limit your team in any way.