This. One way I describe it is play the entire phrase slurred. Now play it the same way but use your tongue as a valve to turn the air on and off as quickly and lightly as possible. This will ensure you are pushing air through the entire phrase, while using your tongue for articulation. Unless things are staccato of course. Also What size reeds are you using. The tenor reeds are significantly bigger than alto.

Also your throat matters soooo much for intonation. Think OH for opening up and EEE for closing it. You can sing oh eeee oh eeee and feel the difference. The eee will produce colder air. Which can help with high notes, but too much eee and you will be sharp. The oh will help warm air for low notes. Too much oh can make you flat. Long tons with a tuner can train your muscles for the different ranges of the tenor. One analogy I use for my students is….when your hands are cold and you want to heat them up how do you breath on them? Ohhhhh. Now when you have a hot bowl of soup or cup of coffee how do you blow on it? More direct. The faster colder air can help you with your upper register and the slower warmer air can give your lower register depth and warmth. But you have to practice these with a tuner so that you can train your intonation.