To answer your specific questions:
Yes, adding both of those tangs is too much of a bioload, presuming that you've an average sized skimmer for that tank, an average amount of live rock, and perform an average number of water changes.
If you insist on doing it anyway, then both should be added simultaneously. Tangs tend to be quite territorial, and an already established one may take a very dim view of another one appearing in the tank.
No, they won't be "good for awhile" unless your definition of "awhile" is 2 months. Tangs, particularly juvenile tangs, are some of the fastest growers available to an aquarist.
Finally, you do actually need to be lectured - at least on proper forum etiquette. Unlike many other forums on the 'net, this one is properly moderated and the moderators take a very dim view of rude behavior. It's called a "forum" for a reason - anyone may chime in with any advice at any time; there's no rule or compunction to only address the original poster's specific question and only the specific question. It's also extremely bad form to ask a question with the goal of validating a choice that you've already made, and then arguing with contrary opinions.
The first issue (rudeness) may get you sanctioned or kicked off the forum entirely depending on the severity of the rudeness and the discretion of the particular moderator reviewing your posts. The second issue is simply poor behavior, period.