I personally would not put a loader on a 2WD, gear transmission tractor, especially if it doesn't have the optional power steering.
IMHO I think it is Ok on a reasonably heavy machine, especially with a heavy counterweight to keep good weight on the rear axle - not just for grip but primarily for stability. Guys over here seem to put a loader on the smallest, lightest Shibaura, Kubota or whatever other machine they can find, then proceed to tip it over as soon as they fill the bucket!
Almost all experienced operators on here realise (and another reason for reading these pages is for information and advice/guidance) that the rear axle weight, coupled with the bucket height+weight, (add surface smoothness, level of grip, angle of slope and/or tightness of turn if applicable) is all that keeps the machine stable. There is a lot to keep in mind, and I'm the first to declare I don't know it all - only a small amount!
I do however agree with your point about power steering, which I am fortunate our old MF 40 loader has (steering was really heavy with insufficient P/St oil).
That machine has basically a MF65 gearbox & rear end, wide and heavy, with really heavy cast-iron rear wheel centres and tyres filled with water for added
ballast. Also being a loader, an up-rated front axle, wheels and tyres. My MF135 was quite unhappy about lifting a rear wheel off it and back on again. I also had a heavy soil aerator on the 3pl for added ballast when I was cleaning the 2-3ft of mud out of an empty water dam here. It was working a recently-reconditioned 3-152 Perkins engine rather hard, after running it in whilst aerating about 60 acres for a friend, but I was never uneasy about it's stability climbing up around the side of the dam - it rocked a bit over an unexpected bump where I was holding the lever ready to drop the bucket (one foot or so) to the ground instantly, but it didn't even threaten to tip over. I did, however, wish it was a 4cyl Perkins - that additional 12 or 15 horsepower would have been really handy, but for what it is, it's really strong now it has run-in!