And consider this-
Heavy tanks like the Kingtiger and Tiger are ALREADY penalised enough on two counts:
Firstly, their speed in open terrain
is only 3 hexes (compared to the PzIVH's 4 hexes)
Secondly the heavies suffer from the 'Heavy treading' trait which
slaps a severe efficiency penalty on them when they try to move through certain terrain.
Here's the blurb from Terminators excellent 'Traits' listing-
Trait 56- Heavy treading: "The heavy weight and large size characteristics of this unit prevent it from entering certain terrain types."
I just ran a series editor tests (vanilla OOB v 7.1.6) in my laboratory to check things out by plonking the game's terrain types on the map and then running tanks into it to observe the effect-
Note the Kingtiger has the 'Heavy Treading' trait-
And some units have the
'Trait 19- Light Tread: "Lower efficiency loss from terrain disruption"
The following test results were observed-
Only SWAMP incurred an efficiency loss- Kingtiger +2, PzIVH +1, BT-7 0.
All the other terrain incurred no eff loss for any of the 3 tanks (and they were all prohibited from entering Mountain, Dense forest, Rough desert).
For good measure (and fun) I also tested them in Jungle terrain, and obtained the following results-
Kingtiger +4, PzIVH +2, BT-7 +1.
Summary- the big slow, lumbering tanks of all nations suffer enough, so to also slap an "Unreliable" trait on them too would be cruel in the extreme (sniffle)