Can't get my defence/mid combo right, HELP!

[Mitchzdream22]

Hey guys, really struggling with my defence and midfield combo. Can't seem to get the balance right this year. This is what I have at the moment. Any advice greatly appreciated :)

Defence: Goddard, Gibbs, heppell, Armstrong, vlastuin, goodes (pittard, colqhhoun)

Mids: ablett, boyd, cotchin, pendlebury, fyfe, wines, crouch, o'meara (mitchell, viney)

Rucks: jacobs, leuenberger ( currie, witts)

Forwards: franklin, zorko, rockliff, walker, lecras, macaffer (Rowe, lee)

$2500 left