Very strong team with some nice cover everywhere. Would you consider dropping Briggs to Jack Williams, gives you $500k to upgrade Sheldrick or Ashcroft to Petracca
You already have 23 premos, just have to have them in the right configuration/hope that your injured ones return soon.
I would look to trade a ruck for someone who provides good DPP cover/looping ability. If you trade Ashcroft at the same time you can probably get an elite midfielder and repurpose one of your existing premos as the 23rd man.
Ensuring you have a good FD setup would also be a priority if I was in your position. If you reconfigure your team how you want the final side to look (all premos on field and in their usual positions) it will be easier to see what DPP is most additive, but I suspect it’s DF (eg Dewar) or MF (which you may have covered subject to Drury’s donut draw, which I recall as being good).