Depends what you are putting it into and what your are stopping it swing for.

If its because the wind changes then it'll need to be able to hold the boat same as the front if it goes 180 degs, especially if the consequence is a wrecked boat swinging on to rocks or other boats etc.

If its going into sand those folding ones are useless (if its what Im thinking of)

Another thing to remember is that when the tide/wind/current is pushing a boat beam on, the loading is far greater on the ground tackle.

Trivia info , a stern anchor setup as such is usually called a kedge though thats technically say for a landing barge to hold the stern off the beach, or a grounded vessel to pull itself off.

Or where you moor bow onto the beach with a stern anchor to hold you off.

I use a crappy Danforth for beach mooring.

 The practice of fore-and-aft mooring has long been common in river and lake fishing over east, to enable all occupants to fish down the tide and maximise useable gunwhale length . One anchor capable of holding the whole load goes over the bow, back across the tide enough to have twice the rope out you need, then drop another over the stern and then pull yourself forward until you are halfway between the two, then tie off.  No issues with tide and wind at variance making you swing around. Obviously, if you are hanging across the tide, there is more hull drag than laying directly into it, so your anchors will need to be of a suitable type and weight for the kind of bottom you are anchoring on. Very commom to see boats fishing like this--Luderick ( blackfish) , and Bream are the usual targets. You don't do it in deep, swift wide channels, like the lower Hawkesbury more your estuarine lakes and rivers like the Georges. I imagine it would work fine somewhere like Walpole, I've used it in the Murchison.

In the river you can get away with whatever holds, if you are doing it in the ocean I  have always used a rock pick on the smaller size of suitable to hold the boat, that way if you happen to get picked up by a swell the rear rock pick will straighten and allow the boat to swing as it should rather than get into trouble from a breaker or big roller.