I, recently, rented a post hole auger designed to go on a skid steer. Worked fine on the front of the TC 40 although it turned slowly. Much better than the 3pt auger I own. I also have a bale grabber for round bales of hay. Works fine, might want a rear weight, won't lift the heaviest sileage bales well. I also use the rear remotes for a variety of hay implements: mower, baler, tedder,etc. I have a Stump Grapple on mine. Best attachment I ever bought. Dig out rocks, stumps, pick up tree-length logs, etc.I believe that machine should have about a 9-10gpm flow rate from the remotes? That's just below the low end of a standard flow skid steer.
For a concrete mixer I wouldnt worry about it to much. What's there spec for needed flow?