I have no issues putting fallow bucks in the largest size heck basket, a length of rope or a ratchet strap around a neck to secure that on the basket whilst you lift the back legs means it quite easy to do, a ton bag then fits over with a strap to secure the load. I am not strong as sit at a desk all day!
My basket is rated to 90kg. I’ve had double that off-road on it with no issues.
I do know that heck pack make a winch and ramp that clamps onto the basket too, have a look on the German website here
Heck-Pack Hand Cable Winch for Tow Bar Mounted Carriers in the GRUBE shop