If Lachie wants to go, he'd probably want to go to St. Kilda because his brother plays there, i think there are three ways the trade could go
If done early in the trade period (If we don't have McCarthy)
Weller + Pick 16 for Pick 5 which we would trade to GWS for McCarthy
If done late in the trade period (If we want a first round draft pick)
Weller+ Pick 16 for Pick 5, which we use on a high profile player
If done late in the trade period (If we want another player)
Lachie Weller for Blake Acres
Blake is originally from Perth, is tall, can play midfield, defence and forward (not sure about the last two, don't quote me on that) and hasn't had many oppurtunitys