Probably depends on the form of the new bowlers. But yeah, it's a weird situation.
Basically, between O'Brien and Christian, you have just enough wicket-taking and run-scoring to stem the bleeding. They give some resistance if the top-order has a bad day (which is frequent; Borgas is Norf-like and Manou is a bit up-and-down right now) and stop the bowlers from getting into the bunnies too early. And they bowl tightly when the other bowlers go for runs, doing just enough with the ball to be hard to get away and poach the occasional wicket, valuable roles on Adelaide Oval. Basically, both do just enough to keep any competition for their places away. Which is minimal because the SA grade cricket cupboard is very bare.
When SA is at full strength, the order will probably look like this;
Harris
Smith
Klinger
Blizzard
Ferguson
Manou
Christian
O'Brien
Cassel
Edmonson
George
As things stand, there's probably not a lot of wiggle room for that line-up. You can't drop Christian for a batsman because then you don't have much to shield what are effectively 3 number 11's and they're not taking enough wickets to compensate for that. You can't drop O'Brien for Bailey because he gives away too many runs, takes only a few more wickets and is, at best, comparable with the bat.
What would be ideal is if Christian or Richardson was able to bat 6 and bowl a similar number of overs like Joe Scuderi used to and push Manou down to 7 I reckon. If the new bowlers and top-order show some form, though, they might be able to get away with dropping both all-rounders, picking a spinner and a batsman. But with the mix of guns, solid pro's and all-rounders they have, there's not a lot that can be changed.