Retro Alternative Rules Discussion

Retro has basic infantry combat rules for ASL / Squad Leader in 6 half-letter pages, which is excellent. Tank rules are a bit on the thin side.

New rules should be less than 1 page, and highly simplified.

Retro Additional Tank Rules

 Button up This allow give the tank commander a bonus for sticking his head out, but at a risk of injury, which is realistic and interesting in game terms.

Tank Leader This is a very simple method of  representing crew skill.

Turrets - Tanks have turrets for a reason, fast turrets give effective fire over a wide radius.

Guns vs InfantryA Retro Stewart 37mm gun kills an entire squad on a 9 or less with 2 D6,  0-6 hexes, no modifiers. This is very unlike Squad leader. The new rule would require a 3 or less for the Stewart (Crescendo Of Doom requires 3 or less for 50mm on the IFT, column "6/50mm", see below), but an ISU-152  does kill an entire squad on a 9 or less. But now the "kill" is 36+ on the IFT, a kill on 7 or less, otherwise probably broken.
So this is close in effect to Crescendo of Doom, and easier than Retro.  You just say "37mm, is 4cm, so diff is 4". You don't have to look up the gun factor for 37LL.
If you enemy is Crew Exposed you can shoot at the crew as an infantry target. So a 150mm howitzer has a good chance of stopping a CE vehicle.

Hulldown This is just behind a wall. Wargamers say "What about reverse slope?"
Reverse slope leaves you silhouetted against the skyline, with a huge blind spot in front of you. This is suicide, unless you are in a well planned defensive position. Driving to the top of the nearest hill is great in PanzerBlitz, not in real life.
The Wall token lets you add a prepared hulldown position for your Golan Heights scenarios:

Retro Modern New Rules

HEAT weapons and ATGMs have to be modelled. New vehicle counters should have HEAT and non-HEAT Armor and Gun Factors.

New rules should be about 1 page.

1) HEAT Gun Factors are essential postwar. HEAT armor factors come in in the late '60s with the T-64. These numbers should be squeezed onto the counters.
2) ASL/COI has a box or a circle around numbers to give the turret a bonus or penalty, but 2 number with a line in the middle allow turret armor upgrades, like Leopard-1.
3) ATGMs have vague minimum and exact maximum range, hit probability on live targets doesn't vary much with range:

4) We can keep the Retro Panzerfaust and Bazooka rules for modern squad antitank weapons.
5) Heavier infantry AT weapons such as SPG-9 RCL can be double range Bazookas.
6) If you move to encounter an enemy tank it always shoots first, and it may have a 50/50 of killing you, so move and fire at a penalty seems reasonable, with stabilized guns giving an advantage. This is move, stop, fire rather than fire on the move.
7) Part of the frontal armor may have reactive blocks, which may or may not get hit:

Here we have a new tank counter. 
The Gun Factor is in red, "31" is front armor. "7" is side armor.
"1" is a 1-column right shift on the Armor Combat Table (optical rangefinder).
"42h" is the HEAT Gun Factor, which the firer can chose instead of the red number.
The "31/42" is the HEAT front armor factor Turret/Hull.
There is no HEAT side armor value, since any HEAT warhead will work on the side.
The ASL counters don't have the gun factor on the counter, so this is easier.
Stabilized guns get chevrons for gun stabilization, a right shift on the Armor Combat Table for each chevron.

There are Generic Recoilless guns and Generic ATGM classes, since there are a hundred of the things. You can make specific Milan-2 Counters if you like.