This is a somewhat flawed approach to the upgrade plan. If you don't start the Macrae types you should be generating an extra premium elswhere, that's basically the trade off. It's also important to remember that they're not "one up, one down" plays, they're "1.5 up, 1.5 down" and need to be planned around accordingly. I do think the trade boosts are going to make this equation a lot easier this year.
That said, the more important takeaway for your focused area of improvement is how you ended up in the situation of fielding dud rookies that forced your hand into underwhelming trades. That sounds like you created structural problems in your side which is more often than not a starting team problem.
This can happen in multiple ways but I'd look at last year's team and see if any of these applied:
1. Picked dud rookies - This is the obvious one and probably the hardest given there is such a randomness to it all but if you had any standouts perhaps assess why they failed. Brockman for example was a common bad pick last year, small forward with sketchy JS is the explanation but it's easy to go overboard on flash players who have a good preseason game and kind of miss the forest for the trees that they're still a small forward with sketchy JS, just an example. Bruhn was another example of this that comes to mind and there's been a ton of them over the years.
2. Structural errors - This can combine with the above very easily, last year for example there were people still trying to field 1-2 premium defenders despite there never being more than 4 or 5 rookies putting their hands up at any point through the preseason. It's really easy to get fixated on a structure and then pick dud rookies to try and fill it out or even on a couple of breakouts that you really wanted and sacrifice everything else to fit them in.
3. Bad rookie trading - A lot of the time we will trade out a "better" rookie now because they're worth slightly more than a bad rookie. This can be hard to pick also but often you've got rookie A who has strong JS and is scoring okay but has a bad game and we jump to dump him, normally replacing with a weaker rookie but, more importantly, also keeping another bad rookie and then relying on them to play instead which suddenly means you're fielding a dud and that's when the panic can set in! Sometimes there is huge value in knowing which rookies you're happy to make 20-50k less on for their scoring over the next 6 weeks and quite often if they're strong enough you want to field them they actually end up making more cash by holding. Basically it's trying to trade out your weakest rookies first and field your strongest rookies longer. The ideal world is when you trade a strong rookie, it's for a similarly strong rookie to replace them.
4. Poor DPP setup - This can often allow you to avoid dud rookies starting in specific spots, probably not as relevant this year with the rookies set to all change but the ability to be flexible as to what rookies you're starting instead of locked into a set couple can definitely change this aspect of the game.
5. Rolling Donut - Did you start one? If so where did you start them? People love to get these and will often pick them on an already weak line because "there's a lack of rookie options" which actually just compound the problem in that area of weakness, this links up with point 2 heavily, the logical move if there are no back rookies, for example, is to get an extra premium there and an extra rookie where there is strength in numbers, doubling down in an area of weakness with a worthless pick is a very quick path to dud rookies playing too often. Throw in that you're costing yourself 100-150k and you've actually found a really quick reason for why Macrae feels impossible to get to. As you can probably tell I'm not a fan of these in general! I've been playing for a very long time, I consider myself pretty good at picking rookies and I can't recall ever not having a donut by round 4 anyway as some "sure" rookie duds it up, gets injured or whatever. If you're going to pick one though, pick it an area that you don't feel weak, generally that will be R3 (trading and no options exist often) or M10 who can actually swap with a D/M or F/M to provide extra cover/options for you.
If you've managed to avoid all those errors and still fielding dud rookies, you're probably not alone