The Three Point Hitch tractor has been marketed in the USA since 1939. Patents on the Three Point Hitch and TPH hydraulic controls expired in 1955. Since 1955 (66 years) all traditional compact tractors have been designed and produced around the Ferguson Three Point Hitch, worldwide.
The traditional tractor design is generic.
I am tired of trying to guess which one will last best.
That depends on the prudence of the owner/operator. Prudence in operation. Prudence in performing preventative maintenance on time. Employee tractor operation will be intermittently imprudent.
Inside storage is better than outside storage.
I prefer 3-cylinder diesel engines (Kioti) over 4-cylinder diesel engines for simplicity. At 40-hp you can go either way. About 50-hp the engines have 4-cylinders.
Looking at Massey, Mahindra, Yanmar.....
Among these three I rate Yanmar tops. My first tractor was a Deere/Yanmar.
As for parts: (Kubota), Yanmar and Kioti produce almost all tractor components in their own factories, therefore buy few components from outside, relative to other brands. (Deere, commendably, has a plant in Waterloo, Iowa dedicated to producing factory parts for legacy models. Very good parts availability but high prices for legacy model parts, produced in small volume in a union plant.)
wont turn over on a little slope
The spread of the rear wheels/tires is the most important factor in tractor stability, followed by rear tire ballast
. All the tractors you are considering are 66" wide with R1/ag tires. R1/ag rear tires are almost, almost always spread/adjustable wider.
turn around at the end of a row without needing a mile
Dont like itybity tires on the front,
The turning radius of every model is part of its specs.
I doubt there is 12" difference in turning radius among all the models you examine. (It is small front wheels that make tight turns possible.)
Most will have split turning brakes. However split brakes are seldom used in field work today. Split brakes are used when clearing snow, today.
When considering a tractor purchase bare tractor weight first, tractor horsepower second, rear axle width third, rear wheel/tire ballast fourth.