Here's my understading about it in my area. The synthetic and the 5w20 say WPP on the bottom meaning Warren Perf. Packaging. which is a division/subsidiary of Warren Distribution. For those products they blend their own product and (as said) is said to be the same as MAG 1 oil and trans fluid.
The other products say WNE on the bottom. That could mean Warren NorthEast as there is a similar plant in WV to the WPP plant in Iowa. Whether the product made and bottled there is the same as MAG 1 products, I don't know. The other quart bottles that used to be shaped like Exxon SuperFlo, MC5k were Exxon, but the quart bottles now all have the same shape as the old Havoline (not DS) bottles.
As for the ST syn, I'd spend the extra buck a jug, and go with QS UD/HP.