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In terms of durability(less hp but more armor) and AI the comet is on par with a vet 0 panther and has weaker AT performance. This is slightly offset by more utility with commander upgrade and smoke rounds but it isnt worth 10 more fuel than the panther.
When it comes to surviving.
Panther Vet 0 Comet Vet 0
Target size: 24 Target size: 22
Sight: 35 Sight: 45
Speed: 6.6 Speed: 6.9
Accel: 2.4 Accel: 2.2
Rotate: 30 Rotate: 32
Armor: 260/90 Armor: 290/110
Health: 960 Health: 800
Abilities: Abilities: War speed,Hammer tracking, Smoke round, Grenades
So Comet is superior to everything accept HP and acceleration.
Panther Vet 3 Comet Vet 3
Target size: 24 Target size: 22
Sight: 35 Sight: 45
Speed: 6.6 Speed: 9
Accel: 2.4 Accel: 2.6
Rotate: 36 Rotate: 32
Armor: 286/99 Armor: 290/110
Health: 960 Health: 800
Abilities:Blitzkrieg Abilities: War speed,Hammer tracking, WP round, Grenades
So comet is superior to everything accept HP and rotation.
Given that allied TD are superior and that Comet is far better dealing with ATG I would say that Comet has better chances to survive that battle field in unless it facing a Panther 1vs1.
Comet cost is 500/185 Cost of the Panther is 490/185 so it cost 10 manpower more not fuel.