Bear in mind our long-standing policy of only using copytags for companies and brand names when there are associated characters. This is explicitly spelled out in howto:copyright and has been repeatedly affirmed in multiple forum threads: topic #2075, topic #6888, topic #8160.
AMD is a copytag because it has several official mascot characters. I'm not aware of any mascots for the other companies you mentioned, so how do you justify making them copytags?