I think there may be a double meaning to „Mess with the best“ - it can mean both get aggressively involved but also to be part of a unit, coming from the Army term of „Mess“ to mean a room or building in which members of the armed forces have their meals or spend their free time.
So you are part of an elite team, but you can die like anyone. http://www.usingenglish.com/forum/threads/68266-Mess-with-the-best-die-like-the-Rest
Don’t mess with Texas!® (slogan on road signs and in advertisements etc, a. fig)
Leg dich nicht mit Texas an!
Danke arbiter für die konstruktive Hilfe...
to mess with sb- sich mit jmd anlegen/blöd kommen
Möchte aber sinngemäß die Übersetzung wie Oben beschrieben.