Because there are again and again cheaters or/and bug exploiters who somehow are able to get better scores in raid tiers 5 & 6 then it should be possible I want to suggest a simple solution.
How about TS adds a calculation into the game that calculates the minimum damage a player has to receive during raid tiers 5 & 6 and then checks the damage the player actually received in those tiers during the score calculation?
The calulation is based on following simple facts for the minimal damage you have to receive without cheating or “bugs”.
Those facts themselves are based on the minimal damage of the weakest weapons of the enemies (including drones if the enemy has a drone and legs if the enemy has no weapon for range 1), the maximal amount of resistance (including 40% bonus from arena shop) a player can get against electrical and physical damage and the possibility to shut down the enemies in range 3 with heat bomb (including 20% heat bonus from arena shop) in the first turn to avoid taking any damage while that is impossible to do in any other range due to the enemies’ energy and heat caps being to high for any other weapon (even with 20% heat bonus and 20% energy drain bonus from arena shop).
Minimal damage in raid tier 5:

from a tank at a starting distance of
 1 space: 1 point of damage
 3 spaces: 0 points of damage
 5 spaces: 1 point of damage
 7 spaces: 1 point of damage

from a minion mech at a starting distance of
 1 space: 2 points of damage
 3 spaces: 0 points of damage
 5 spaces: 2 points of damage
 7 spaces: 2 points of damage

from the boss mech at a starting distance of
 1 space: 2 points of damage
 3 spaces: 0 points of damage
 5 spaces: 2 points of damage
 7 spaces: 2 points of damage
Minimal damage in raid tier 6:

from a buggy at starting distance of
 1 space: 1 point of damage
 3 spaces: 0 points of damage
 5 spaces: 1 point of damage
 7 spaces: 0 points of damage (VS can drain those 186 energy the buggy has and buggy cannot get in range for shotgun in 1 move.)

from a tank at a starting distance of
 1 space: 1 point of damage
 3 spaces: 0 points of damage
 5 spaces: 1 point of damage
 7 spaces: 1 point of damage

from a minion mech at a starting distance of
 1 space: 2 points of damage
 3 spaces: 0 points of damage
 5 spaces: 1 point of damage
 7 spaces: 1 point of damage

from the boss mech at a starting distance of
 1 space: 8 points of damage (Increase the distance to 35 and get hit by Nighteagle’s minimal attack 152  player’s PhysRes up to 145 = 7 damage + 1 damage from drone)
 3 spaces: 0 points of damage
 5 spaces: 1 point of damage (Increase distance to 7 = go to corner. Now boss deploys drone and must teleport to the position at distance 2 in fromt of you.)
 7 spaces: 1 point of damage (Either go to corner 1 space back or cool down or fire weapon with range 48 or deploy drone. Then again boss has to teleport to 2 spaces in front of you after deploying its own drone.)
Then the server calculates the minimal damage based on the enemies and their starting positions in those 2 tiers.
For example the raid tier 5 from Saturday, October 6th 2018:
 1st tank at starting distance 1 = 1 point of damage
 2nd tank at starting distance 1 = 1 point of damage
 1st minion mech at starting distance 3 = 0 points of damage
 2nd minion mech at starting distance 7 = 2 points of damage
 the boss mech at starting distance 3 = 0 points of damage
==> Total minimal damage from this raid tier 5: 4 points of damage
For example the raid tier 6 from Sundday, October 7th 2018:
 1st buggy at starting distance 3 = 0 points of damage
 2nd buggy at starting distance 7 = 0 points of damage
 3rd buggy at starting distance 1 = 1 point of damage
 4th buggy at starting distance 1 = 1 point of damage
 the minion mech at starting distance 1 = 2 points of damage
 1st tank at starting distance 7 = 1 point of damage
 2nd tank at starting distance 5 = 1 point of damage
 3rd tank at starting distance 1 = 1 point of damage
 the boss mech at starting distance 3 = 0 points of damage
==> Total minimal damage from this raid tier 6: 7 points of damage
Finally before calculating the score for completing raid tier 5 or tier 6 the system will check the damage received by the player during that tier.
If the player has received the minimal damage possible or higher, e.g. 4 points of damage or more in the tier 5 from October 6th 2018, then the score calculation proceeds as normal.
BUT if the player received less damage than the minimal damage possible for that tier, e.g. 3 points of damage or less in the tier 5 from October 6th 2018, then there will be a factor of “1” be included into the calculation.
So bug exploiters and cheaters would then have their score reduced by their unfair score instead of increased.
As such there would no need to look out for the cheaters or/and bug exploiters in raids anymore because they would be punished for cheating or/and exploiting a bug by the game itself.
P.S.:
As far as I know there is no need to implement any control for the raid tiers 14 because you can destroy all enemies there without taking any damage no matter which starting distance they have.
So as long as the tiers 5 and 6 are controlled in this way cheaters and bug exploiters will not be able to steal ranks.