The basic theme of these rules is that if it is present in the 'standard' combat rules of Traveller, it will translate over _directly_ to mass combat. So, if a unit is in cover, it uses the same cover rules you are already used to.
The basic idea here (aside from keeping things simple) is that we can later add pretty much any rules we like to Traveller, and they will automatically be compatible with mass combat.
These rules (and the unit creation rules) only seem to cater for forces made up of infantry. What is the Endurance stat for a force of tanks or for a force of mechanised infantry in APCs? Is it the number of personnel still? If it is, how do you account for the fact that the unit's fighting ability depends on the vehicles? Similarly a unit of artillery. Or water vessels.
At the moment it feels like you have created what should be called "Mass Infantry Combat Rules".