A couple of clinical forwards, a top defensive mid and a central defender would be a great step forward. Ideally I'd like another more attacking midfielder to support Mac Allister as I think Szoboslai, Jones and Gravenberch lack impact.
Tsimikas is fine to cover Robbo and Trent and Bradley should be more than enough at right back. Robbo and Salah in particular will need replacing soon so we should be planning for that though.