I agree with this and this is the point that makes me want preuss as someone who watches a lot of games rather than going off pure numbers. He's not just an average ruck who has landed in a number 1 ruck role, when he first started getting games at North people started questioning if it was viable for North to trade Goldy because Preuss was that impressive. Then got traded to Melbourne and sat in the seconds which I think is why people have forgotten that he's a genuinely good prospect. I think he's at the right age and collected enough experience from two of the best rucks in the last decade to have a big impact at GWS. There is no chance that GWS go back to Mummy, in my view they've recruited Preuss so that they never have to die on that hill again. The game counts in previous seasons don't count for a whole lot because he was stuck behind Goldy and Gawn. He got one game as a lone Ruck in 2019 when Gawn was injured where he put up 140 so he's definitely capable of grabbing an opportunity with both hands. I sit on a different side of the fence to the people who've been burnt by mid price rucks, I always pick the premium rucks and regret not picking the mid pricer. I avoided Witts, Lycett and Naismith and copped Gawn's injury when Witts broke out, picked Stef Martin over Lycett when Lycett would've been a perfect stepping stone to Grundy when he broke out and it cost me about 20 points a week and last year I think I broke even by picking Gawn over Naismith because Naismith owner's got an easy trade to Pittonet and Gawn only worked out because he had his best ever season or I possibly would've regretted it again. Funnily enough after saying all this I still haven't learned my lesson and have got Gawn and Grundy because I don't have a pair lol.
The question is what are your expectations.
Firstly... What can Preuss do? Quantify it.
Secondly... What will the ruck premium level be? Quantify it.
If you come up with 105 for Preuss but 125 for the ruck, all you've got is a good cash cow in Preuss and a gap to close later (not a problem). Preuss still makes sense as a pick but know what he is. He's still just a rookie averaging 71 on your field. That's all the value he presents in this scenario assuming you break even on that 180k (aka it doesn't generate additional value).
Alot of people seem to only be looking at one side of the equation with Preuss over Gawn. I think there is just as much chance that Pruess makes 100k as there is of Gawn dropping 100k. If Gawn drops 100k you have effectively gained a trade as it is equivalent of a rookie downgrade.
People will come at me with the argument you would have had to wait until round 15 to get him at a cheaper price. Yes you would have but he also started at 695k not 755k and we all know last year that those with higher averages got a bigger piece of the pie that won't happen again this year. Started at 690k in 2019 and dropped 50k in 6 weeks. Will be interesting to see what happens this year.
I actually think this is a really bad thing to consider with Preuss. You're trying to tie two independent variables and relate them to make a bad choice (by your numbers) look like a good choice. The only relationship between them is that there are only 3 ruck spots and so if you like two others more than either of them you have to pick only one of them. If you've found two rucks better than them, then please do share
If Preuss makes 100k he's a bad pick, regardless of what Gawn does independently of him. This isn't a binary option between two players. If Preuss makes 300k he's a great pick, again, regardless of what Gawn does.
If Preuss averages 105 and Gawn maintains his average, Preuss is still a very good starting pick instead of Gawn. If Preuss averages 60 and Gawn averages 95, Preuss is still a very bad pick.
You need to set your parameters on what a ruck keeper is likely going to be and you need to set your expectations on Preuss. Assuming you're like most and set that at ~120+ for a keeper and 105 as a high end outcome for Preuss, then Preuss is being picked over other rookies and that is the group you should compare him with.
I think too many people are making it a Gawn vs Preuss comparison, you can quite easily pick neither of them in your starting team and there's an absolutely sound case that this is the best option. You can pick both of them in your team and there is a great case this is the right choice. You can pick both of them with Grundy and have it be the right choice.
But don't pick Preuss if you don't think he's far more likely than not to go 95+ regardless of how you feel about Gawn, Grundy or anyone else. Unless you honestly don't think you can fill your team with 123k rookies who average 60, then Preuss at anything under 95 as an average is a losing pick to all them and they are his peers unless you legitimately think he's got keeper numbers in him!
Your logic is akin to saying that some rookie who doesn't play is a good pick because you didn't start some premium who fell 100k.