In your situation I'd try towing the two kayaks in-line astern, with the Cabo in the rear (i.e. your tinny -> Prowler -> Cabo following last, all in one line). The pressure from the Cabo will keep the Prowler in-line and lessen the risk of it surfing to one side of the wake and rolling. You will also find it may be beneficial to run a drag rope off the stern of the Cabo to keep in in line too. I've used a 5m length of 20mm rope for this.

 Couple yrs back we came across a fully loaded kayak out in the middle of clevedon flats...At 1st thinking the worst, a call back to the club house  found someone had it float away, when they went back to lock the car at Duders.

As above posts, soon found towing was not going to be as easy as it seems..

 So we pulled it up along side onto a cleat midships with the bow a bit high.. It sort of hung out, but was stable.

 If was going to tow for any great distance we would have put it across the deck up front or pulled it in over the stern... both considerations/ alternatives we discussed before hooking it up on the cleat midships.