I have only read the summary of each so far but the number of CC on board seems to be the least of the problems experienced!
If you read further you may see that, in my opinion, the number of cabin crew did assist with the evacuation and it's outcome.
Ansett 727
There was two flight attendants assigned to supervise the overwing exits. TWO(!). One left and one right (they would not be there under the new ratio). The one on the right noticed what she thought was burn marks or oil on the wing and blocked the right overwing exit. It turns out the discolour was from the APU exhaust (I think?). My point is that a trained pair of eyes noticed a possible hazard. An ABP may not.
The left overwing flight attendant noticed pax running to the wingtip and began to yell "follow the arrows" to direct pax to the back of the wing. That was not procedure at the time and was adopted not only by Ansett after this incident.
Then there is the little(!) matter of Ansett believing that all main door slides would inflate automatically. This is how they trained the flight attendants and it was not the case. The forward main doors were opened and the slides did not inflate (as they were manual inflation only). The FAs immediately pulled the manual inflation handle. Would an ABP (who has not been briefed)?
NJS 146
Two paxing flight attendants assisted in the relay of information to the flight deck and assisted pulling passengers of the slide. The very short slide on the 146 can allow for pax to bundle together at the bottom. The paxing flight attendant at each slide pulled the pax clear.
Passengers in this incident comment that they could not see either operating flight attendant from the cabin (at L1 and L2) during the evacuation. Another passenger commented that other passengers collected hand luggage and held up the evacuation. If more crew had been onboard both situations may have been avoided.
Jetstar 717
Although a very light passenger load, the overwing flight attendant (which will be the position dropped under the proposed legislation) played a pivotal role in controlling the evacuation. She saw all pax head to the front and directed some of them to the rear to avoid the bottle neck. When she then noticed a bottleneck at the tailcone exit she redirected the remaining pax forward.
The L1 flight attendant physically prevented a man from jumping out during door opening, before the slide had inflated. Would an ABP have known the slide was yet to begin it's inflation sequence (the door was 3/4 the way open and it is common belief of pax that the slide would have been ready to go)?
These are just example and, of course, my opinion. The cabin crew in the above incidents also made a couple of procedural errors, I will admit. This happens in almost all evacuations. I just wanted to highlight a couple of points which I think demonstrate the position that more cabin crew is only better from a safety perspective.