I am not arguing with anyoue cutting small trees with short bars . But as to sharp chains , I've watched Alot of utube vids of guys bucking cookies and its quite obvious their chains are not truely sharp .
When someone brags that they can cut 70" on the stump timber with a 24" bar . Sorry but I'm gonna call b.s. in the most vehemint manner .
But anyone can use what they want . Just don't claim a short bar works as well as a longer bar in many situations .
Why if I may ask? I don't see anything impossible about cutting a 70" diameter tree with a 25" bar. 25x3=75 when you minus the spike grab of an inch or two that puts the tree right at about 70" or 3 times the bars lenght. In that big cedar vid the guy looks to be running a 42" bar on a 660 falling a 15 foot diameter tree look at 1:14-1:15, that bar is certainly not 5 feet in lenght. 15x12= 180/42 and thats a tree 4.3 times bigger than the bar yet they felled it. Now it definately takes skill and experience no question about that.
I have not met many folks have recieved any training beyond what they have seen from family and friends or if they were motivated read. I have not. Even many of the commercial cutters do not get much beyond a safety seminar and some "on the job training". If the OP does not need a 28" bar mounted to his 441 to cut what he is cutting then why not use a 20". If he is physically able to bend the body parts needed to use the shorter bar then good for him. A 28" bar in a 16" locust stand in as much of a pita as 16" bar in a 36" maple for me so why not run what he wants.
I always kind of figured that the "European" techniques were an effort to slow down production, create a specialized work force and reduce waste with an emphasis on increased safety being it's most "marketable" an enforcable attibutes.
IJ, the 20" bar a 441 is pretty standard around here so I would look for other reasons as to why the chain broke.
Here in Ontario Canada for example there is a serious lack of training when it comes to timber fallers. There are 2 courses that I am aware of- one is a chainsaw safety course which runs for 2 days the first day they teach maintenance and on day two they teach falling. One day is certainly not enough. However this course is not required to work as a timber faller. What they do require is a skidder+cutter course which runs 3 days and is evenly split between cutting and skidding. 2 1/2 days,provided the extra and not required course is taken, is hardly enough to teach about timber falling. But how can a 1 1/2 day course make someone qualified is beyond me.