The commander's blueprint contains this piece of code:

Veteran = {
    Level1 = 20,
    Level2 = 40,
    Level3 = 65,
    Level4 = 90,
    Level5 = 120,
},
VeteranHealingMult = {
    0.1,
    0.2,
    0.3,
    0.4,
    0.5,
},
VeteranMass = {
    1000,
    1250,
    1750,
    2500,
    3500,
},

On the wiki, I only found explanations for Veteran:

Veteran define how many kills for each veteran level are required.

Veteran = {
Level1 = 'integer', <Define how much kills are required for reaching veteran level 1>
Level2 = 'integer', <Define how much kills are required for reaching veteran level 2>
Level3 = 'integer', <Define how much kills are required for reaching veteran level 3>
Level4 = 'integer', <Define how much kills are required for reaching veteran level 4>
Level5 = 'integer', <Define how much kills are required for reaching veteran level 5>
},

However, as far as I know, veterancy is awarded not for the number of units killed, but for the mass of units killed. This confuses me.

Could you clarify these lines ( Veteran, VeteranHealingMult, VeteranMass ) and what they actually affect?