Depends how narrow/weird the placement is. C4 head width is pretty wide.
Brolga and Mantle I think we used pink and maybe red tri-cams, blue/green/yellow totem basics (ie aliens, approx 0.2 thru 0.4) and C4 0.5 thru 2 or 3 in the horizontals. The totems are nice in that the head is narrow and metal a bit softer so they tend to stick in place well. Cammed hexes (DMM torque nuts) can also work surprisingly well in the larger horizontals ;-)
The tri-cams will often go into weird/flared/shallow/narrow pockets where a cam won't stay in so well or where the oval shape may bend cam lobes if you fall. If I had a smaller (black) tricam it would have been useful too. Tri-cams are pretty easy to place, but your second will need to understand how to remove them or be in for a lot of frustration. You can certainly get away without them, but a pink may be fun to have and play with.
RPs (or DMM IMPs and brass offsets) are always useful, often opposed in tapering horizontal seams.
Skink doesn't need much in the way of very small gear from memory.