Yes, all trombones and euphs (BBb basses) are concert pitch IF played in bass clef. Think about it, in reality, all instruments can be written in concert pitch, but they are not done so. Eb Tenors, Bb Cornets, Bb Fluegels, Eb basses are all transposing. Your idea of what note do you tune to is a good example go how to think about it. To tune to Bb, cornets, baritones and Fluegels play "C" written.
So do trombones written in treble clef. Eb instruments are usually up a 4th or down a 4th (major or minor depending on whether you are transposing up or down).
In a symphony, "A" cornets are often used. Bassoons in bass clef are in concert pitch. Often a xylophone is written using a grand staff (in concert pitch). Tympani are written in concert pitch in bass clef. In a marching band/drum corps the tenor drums are written in treble clef with 5 of each, all tuned a minor third apart. Bass drums are in bass clef and again a minor third apart.
That is why I think Sibelius and/or Finale are a good investment if you do a lot of work. You can write it in concert pitch and both programs will transpose the parts, whether writing for brass bands OR symphony orchestras. I personally like directing from a concert pitch score. C, C#, F transposed is often C, E, F# (transposed). Concert pitch makes it easier for the MD to find out if it is published incorrectly OR played incorrectly (you would be surprised how many errors are made in published parts).
People like Eric Ball, Philip Sparke, Lovatt-Cooper, John Williams, Richard Rodgers, Sousa, Karl King, etc were (and are) more than just musical geniuses.