Putting further thoughts. Instead of callin range nerf! We can beautify it as a AT refresh.
From high level looks like this
40 range
Med tanks no changes
45 range
Call ins changes, standardised them since they do AT and AI brawling well. IS2, Pershing, Tigers, Crocodile (ok poor croc but...)
50 range
Panther no changes. As it sits between AT prowess of TD and AI of callins(loosely put AI..)
55 range
Jp4, Jackson, su85, firefly. Superb AT prowess that gains sweet vet but with zero AI. (hmm jp4..)
60 range
JT, Ele, ISU152
Heavy TD call in, self explanatory.
Puma, M10 - squishy guys like older days of 60Td, seems fine unchanged
70 range
Big Pak and Big Mac Pounder, no change. To counter heavy Td
I like the idea, but there's a few critical things I'd change.
1. Croc at 45 range would actually be a
massive buff, if we're talking about the flame attack. If we're talking about the cannon (and so, the normal Churchill, too), this would still be a +5 range buff; I'm not entirely convinced the churchill needs that range increase.
2-A. I think moving the heavy TDs to 60 range would be a bit too much of a nerf. Their main weakness is horrible mobility and a lack of a turret, but their advantage is +10 range over any other TD. Reducing their range to only +5 over other TDs would mean they would be incredibly easy to "poke" at, considering their awful rate of fire. Additionally, it means less "reaction time" for the Heavy TD to move when being attacked/flanked. I would change this category to 65 range.
2-B. The M10 and Puma both have 50 range right now (not 60). I agree with leaving them as is, but bumping the Puma to 60 range would be extremely oppressive against any form of LV-play.
3. Both Heavy AT emplacements have 80 range right now (not 70). I agree with leave them as-is, giving them +15 range over heavy TDs (no one uses them, so a slight buff could be warranted), or I would reduce them to 75 range, to keep the range-gap the same as it is now.
4. What of the Su76? Right now it's a 60-range turret-less light-TD. I suppose it would also be lowered to 55, however that leaves the STuG in a similar role, but at 50 range.
5. Comet is missing, but it's currently at 45 range.
Updating your list, I would have it something like this:
40 range
Current medium tanks and any other vehicles with 40 range (churchill, etc.). No changes.
45 range
Heavy Call-ins; Standardize Tiger, KT, Pershing, IS2, etc. to 45 range. The IS2 gains +5 range at vet 0 (to bring it to 45), but they all lose any +range veterancy bonuses. Any other vehicles currently with 45 range (comet, etc.) are unchanged.
50 range
Panther, STuG, Puma, M10 etc. No changes. AT vehicles either too cheap or too resilient to warrant 55 range.
55 range
Jp4, Jackson, su76, su85, firefly. All lose 5 range. Dedicated tank destroyers.
65 range
JT, Ele, ISU152. All lose 5 range. Heavy TDs; expensive, slow, doc-locked, and without a turret.
75 range
PaK43, 17LB. All lose 5 range. Static ATG emplacements.