I disagree with the point that getting Gawn is ‘pretty much impossible’. I think any player is gettable as long as you plan for it and have the suitable cash cows.
Flynn to Gawn will likely require 3 trades minimum (2 down, then Flynn to Gawn). It also requires the timing to line up to the plan - what if Gawn drops in price but you don't have the cash cows that have made the cash? What if Gawn doesn't drop in price until later in the season? Would you carry Flynn (potentially -50 points vs Gawn) or would you look for a stepping stone ruck (which now makes it 4 trades to get Gawn). What does this mean for the rest of your team.. are you missing other key upgrades or the chance to get poorer scoring rookies off the field in the pursuit of Gawn?
I think Flynn as R2 only works if you are convinced that Gawn isn't going to have a good year (be it injury, form, covid, whatever) and so you are taking the risk on him. If you believe Gawn will score 130+ or is someone you want in your final team, then I can't see a viable way that you can get him mid season without heavily compromising the trading and upgrading strategy for the rest of your team.