With all do respect... no way. In fact, your scenario may have led to the destruction of the entire regiment.
If Custer had supported Reno from behind... and sent Benteen to help the Arikara's drive off the pony herd... your “standoff” theory would be very possible. Almost a given.
Still, knowing Custer's personality... “Custer's luck”... and his desire for a “big victory”... having Terry “rescue” him from the timber was tantamount to defeat. After the hostile's success at the Rosebud... this battle could only end in one way.
I have no problem with this.
your scenario may have led to the destruction of the entire regiment.
Not necessarily. Custer would have had to retreat from Custer Ridge, that's a given as it's pretty much indefensible ground. But with the three additional troops of Benteen's battalion he'd stand a far better chance of holding his own; at least for awhile.
As for Reno, he could have held on longer than he did. Members of his command said so afterward, although not all were in agreement. What I'm saying is, while Custer's decision to divide his command was bad judgment when not knowing the layout of the village or the area, it was Reno's and Benteen's actions that day that really sealed Custer's destruction. Had they acted more forthrightly, it's conceivable the issue could have become a standoff.
Again, this is all speculation. But I have a hard time with total command defeat had Custer been able to rally his entire command.
“Had Reno not evacuated the valley...”
Janet Reno?