I've noticed in personal study that a translator bias/indoctrinated by tradition bias appears when using the word "preach." When "kerusso," one of the primary Greek words translated as "preach," appears in the context of someone who is not Jesus or apostles it is not translated as "preach" but as "proclaim."
Mark 5:19-20 talks of the man who had the Legion of demons cast out of Him.
Jesus said to him, "Go home to your people and report to them what
great things the Lord has done for you, and how He had mercy on you."
And he went away and began to proclaim in Decapolis what great things Jesus had done for him; and everyone was amazed.
The word kerusso was properly translated as "proclaim" there but when
referring to Jesus or apostles the same Greek word is translated as
"preach." This gives us an underlying idea that only special people
"preach" and the common man "proclaims." But truly scripture offers no
distinction. This same thing also happens in Mark 7:36 & Luke 8:39.
What I'm pointing out here is that there is an unwarranted clergy/laity
style bias that appears when translating the Greek word kerusso. I don't think the word preach should ever be used in a bible translation because when we hear it we think of a
non-interactive monolog (a sermon) which is never what scripture refers