Greg --
Remember that the date cited is June 10th, with much fighting ahead during the month. Johnston's figures for aggregate present on June 30th are 77,441, rather close to the 75,000 figure you cited. It also represents a numeric loss of roughly 25% since June 10th, which is hard to believe.
I will check into this further.
As for weapons counts, the front cover of each brigade report lists the commanding officer, his station, the date of the report, the total present and the number of weapons on hand. Of course these figures are abstracts taken from the body of the inspection report. They rarely show a one-to-one relationship between weapons and men PFD. The ordnance section of the report usually lists some number of unserviceable weapons on hand and a number wanted to completely arm each regiment.
Also, orders were issued to prevent soldiers from taking weapons away from camp if they were going home on leave or going to a hospital. If a soldier's duties on dtail didn't require him to carry his weapon, they remained in care of the ordnance sergeant. Orders were intended to prevent unnecessary losses of weapons and other equipment.