The MT is a recension to begin with.
A recension, as you know, is an alteration of the original text into a new standard.
It was at this time that diacritical markings were added to the text and obvious manipulation of the text took place as compared to its much, much older reference, the LXX.
The vast amount of Hebrew plurals which existed could not all be covered-up by the Unitarian Jews of the time....and so then invented the term 'plural of majesty' to somehow explain how a single God could repeatedly be described in the plural....and, during the Gen 1 creation, they perform scriptural gymnastics, and invoke the angels as being part of the discussion to cover the obvious plurality.
One elementary example in Gen 2.18, reads as thus in the MT recension:
...I will make'...
The LXX, in the same verse, has:
'Let Us make (plural verb) him a helper suitable for him'.
On and on and on it goes....Jews attempting to make a Trinitarian text into a Unitarian one.