There are a lot of misleading points made in that article.
Many of the parts represented in that article as being "weaker" in the 200-4R than the 700-R4 due to their size are simply incorrect.
200-4R front and rear planets are made using a steel carrier ( that appears somewhat cheaply made and weak looking), not cast iron like the 4L60 series units. I see broken 4l60 rear carriers fairly often. I've NEVER seen a broken 200-4R planetary. I've seen worn out ones in both units.
I've never seen the low roller clutch break in any 200-4R except ONE transbraked unit. I've seen them broken in 700s and 4L60E's.
The band isn't really an issue in either unit using aftermarket pieces.
The stock 200-4R input shaft is good for well over 500 HP. I've used it many times.
The stock 700-R4 and 4L60E one is NOT. They will break at less than 500 HP sometimes. They have 3 circuits feeding oil at the back, and although the shaft may be bigger around, it has a lot of material drilled out for the oil passages. It will snap off at one of the axial drilled passages.
The 200-4R forward drum is pretty much THE weak hard part. It's pretty safe to ~400 HP. It DOES NOT break at the weld. I've seen dozens of broken ones and they all break at the base of the splines.
That drum is friction welded from the OEM supplier.
I've seen welds break on aftermarket billet shafted drums that were defective, but not a stock one.
The OD sprag on a 200-4R doesn't fail.
It is the weak link to this day on a 4L60E. The aftermarket has made all kinds of improvements to this unit and there are some pretty neat parts out there now. However the forward sprag is the limiting factor. A forced 4-3 downshift at high rpm with power will kill it repeatedly.
The "one rear bushing" theory sounds good but holds no water in the real world. The 200-4R rear bushing holds up fine. The output shaft doesn't go through a case bushing but it is supported internally by the low support.
What they don't show is the really rigid internal center support in a 200-4R. They don't talk about powerflow, and other engineering aspects that give the 200-4R some clear advantages hydraulically and mechanically.
Bigger is better for some applications, but don't let a biased article be the basis for which OD to pick.
Both units have certain applications they work well in. One simple fact is most builders don't know how to make a 200-4R live, even though they may be good with other units. There are some simple tricks that make or break a 200-4R. Most aren't even secrets anymore.
200-4R cores and parts are becoming more scarce as well, so that influences some builders.