Standard Products are often re-boxed OEM. The 6.2L Ford flex fuel injectors I have in my marine intake are Standard products. They missed scratching the FoMoCo label off 2 or 3 of them. Same goes for the Hitachi MAF I bought for the 2011 Pathfinder when the IAT died in it. The Hitachi MAF had the Nissan part number scratched off it. The Hitachi LS3 MAF is the same one GM dealers sell for multiple times more money. The NEW $100 Autozone Hitachi power steering pump I put on the G35 was the same unit that Infiniti and Nissan dealers charge $700 for. The Standard products knock sensor on my 383 was made by Delphi. The more you can educate yourself on parts the better quality you can get for your $$$. Standard Products, Hitachi and Delphi are typically very good quality.
Last I checked the Genuine GM, Delphi and Standard Products spiders were all the same piece and in the same plastic packaging. Supply chain may have driven the products down other paths, no idea there. At one time 2-3 years ago they were the exact same products. AC Delco is a distributor, not a manufacturer for the most part. Delphi, NGK or NTK and others make parts for AC Delco.
The last new starter I bought was a Remy for a LS. They make the starters for GM.