Easily negated (and surpassed) if you've got 3-4 shooters who can catch fire too. Imagine Curry, Klay and Allen getting hot from behind the arc - there'd be no counter for that. Seeing the margin go up by three every time you're on a defensive trip would put nikkas in a perpetual state of licking their wounds.
What and who are you referring to in this statement? How aren't open threes easy to come by if you have three of the best off-ball players in history running around screens, cutting in and out, relocating,
all at the same time, creating all this chaos until they find an opening? It would take perfect communication, understanding, anticipation, luck, and a great deal of energy to stay with them on every possession - it just isn't possible.
There'd by open shots on every possession, especially with Shaq as their defensive anchor.
"The problem here is, the team of Jordan-Kobe-LeBron-Magic-Shaq would fatigue as a unit, chasing my team around (long before my lineup would on defense), simply because they'd be exerting more energy constantly running around, especially trying to cover for Shaq. The OP Dream Team would predominately score in ISO (well, certainly to a much greater degree than my lineup), meaning not every player on my team would be exerting energy on every defensive trip, especially since in the scheme where all they'd need to focus on is keeping them out of the paint and force jump shots.
My team on defense = staying in front and funneling to help, sticking to their zones, forcing jump-shots, and providing resistance in 1v1s
OP Dream Team on defense = running around screens, endlessly, all the way out to the 3-pt line, and having to deal with constant ball and player movement
Now tell me, which team is going to need to cover more distance and exert more energy on the defensive end?"