As a pastor's kid, then a pastor, and now a missionary pastor, I have observed a variety of Sunday school traditions. Some churches I have attended have Sunday school exercises before class. Others have it afterward. Some have it before AND after the Sunday school class. The traditions of singing, praying, reading a devotional scripture, etc., as well as the expected posture during those activities - sitting or standing - have varied.
While one learns the traditions after attending several weeks, it can be embarrassing, bewildering, and frustrating when one enters the church and does not know where to go, what to do, when to stand and sit, where to find the various recitations, etc. The new pastor will adaps, but the unchurched guest tends to approach the service from a different perspective. In a culture where user-friendliness in every aspect of life is valued highly, the failure to communicate traditions, expectations, etc. is offensive.
Are you erecting unnecessary barriers by your traditions?