On a smaller tractor, you want a blade just wide enough to cover your rear tire tracks. You can move enough material to run out of traction.
I keep hearing about weight, but, and this will likely get me flamed, IMO, technique makes up for weight. I have a 4’ King Kutter XB for the NH and I can dig more material than I have traction.
IMO a box blade is mostly a grading tool that requires careful adjustment and patience….as in this is not an attachment you are going to use quickly. Slow travel speed is a must to get a good result.
Learning how the top link affects the pitch and working action of the blade is crucial. Getting the blade pitch correct allows you to dig, move, spread, and smooth.particularly moving/spreading can be relatively fine adjustment.
The scarifiers are invaluable for breaking up hard pack. I tend to use mine alone and simply break up material before using the blade. IME, that works better for me. YMMV.
I mainly use the rear blade to smooth driving forward. I have used it to push loose material. But IMO, using it as a dozer blade is limited to loose material only.
Soil moisture will also affect how well it works. Too wet it is a mess, too dry it is a mess.
Good luck on finding a blade to suit your needs