Are all hours reported for occupational titles being consolidated into one occupational title be added together to set a rate?

Yes.  

HB 1729 consolidates some occupational titles to be used in the calculation of the 2019 annual wage order.  All calculations relating to computing hourly wages will need to conform to the newly revised list of occupational titles set forth in Sec. 290.257.6(1)(d) RSMo.

For example, for purposes of computing the hourly wage rate for a “carpenter”, the total number of hours submitted for pile drivers, millwrights, lathers and linoleum layers would be added to the hours submitted for carpenters.  The combined sum of all these hours would then be used to calculate the single rate for a carpenter in a particular county.