I'm ideally a medium tall (MT) but that size is a unicorn (doesn't exist). LT sometimes doesn't look too baggy but they're so rare I don't even bother searching for them in most clothes stores.
When a store has a big and tall section it's literally big AND tall, not normal and tall. If you are 2m (6'7") tall you better weigh 300lbs if you want a shirt that fits.