ASANTS, but if it's just coming from your STL, smile and nod while they're talking and then ignore it. STLs tend to be a bit delusional and a bit out of touch with the day-to-day happenings of various workcenters when they're focused solely on the big picture. Let them have their fun and get their "big ideas" out into the world and their power trip out of their system, but just do your job to the best of your ability and they'll be forced to accept it.
Myself and a couple of other people on my team bust our asses, and our STL just keeps piling more on us and it's ridiculous stuff half the time. We'll smile, nod, and agree to do what they ask, and if we can fit it in between our other tasks, fantastic, but if not...oh well. The STL will either be looking at mountains of backstock OR an unfinished 'project' that he threw on us with no warning- but they can't expect a spotless backroom, and BRTMs pulling and pushing research, and pulling all Flex orders within 5-10min of dropping, and BRTMs helping finish Flow's work, and re-pushing all challenge.
It's like that old "triangle" idea- fast, cheap, quality. ...pick two, because you're never going to get all 3. Quality work delivered quickly will cost you quite a bit. If you want something fast and cheap the quality will be terrible...so even if it's on a subconscious level, I think most leaders realize they'll NEVER get everything they ask for, but they still ask.
((maybe that was a bit murky- I'm not trying to say to ignore the orders of leadership, but rather to ignore the stress behind those orders. It sounds like you're a good TM with a solid work ethic and that you've developed a reputation as a good worker. Don't let impossible demands get you down. It's REALLY hard to get over that mental hump- I was exactly the same when I started, but as I gained the confidence of my TL and ETL and started hearing them make comments about how "it'll never get done. Oh well." or "____(STL) has impossible standards" it really took the pressure off me once I realized that everyone up the food chain felt the same way I did!))