[woodruffw]

It isn't particularly correct to say that these agencies have the same purpose. They do similar things, but each has its own remit.

You could maybe instead say that they should be under the same roof, rather than being independent entities. But I don't think this is itself evidence that any of them have been ineffective. Having read some of their reports, OMB and CBO are not ineffective on face value.

(I also don't think any of this is really about curbing government spending.)