I have a Stihl 362 and a 271 both are pro grade (which is worth doing).

You’ll notice that there are 3 different chain thicknesses on saws, the smallest is just about worthless so stay away from those..

the second wide vs. the 3rd is a HUGE difference,

At the end of the day a 440 is the biggest saw and it’s for cutting the stump (huge [bleep])

the 362 is for cutting huge branches, and the trunk - but NOT limbs...

The 271 (MS271) is a lighter strong saw used to cut the limbs to leaves.