I do think the tank crew is a bit bland, especially compared to the other characters. Knox is seen by others as a shirker, and Baume’s a vengeance-driven Frenchman, but even when you seek them out the tank crew doesn’t really give much up. If everything goes well, it just seems like they’re there, and that’s it.
I wonder whether a few more comments from them while you’re between action sequences would help – I remember there being some in Chapter 1, especially the camel/dromedary thing, but not much else afterwards. I also think it doesn’t help how in Chapter 1 you can only have one protracted conversation with one of your crew before Casablanca; that’s not indicated either, so players (as I did) might have expected an opportunity to speak to everyone, not just one. The Casablanca/Algeria gap seems like it would be a good place for that, since it is a bit of a void.
I don’t have much attachment to my crew (yet), but I’d like more. Glancing at the code it seems like breezing through and never taking any damage gets you even less content with the crew. (Perhaps the PC’s tank having a “charmed life” could even be commented upon given how everyone else tends to end up badly)
The thing with the radio is that aside from preventing it from not working (so like maintenance in that regard), I’m not sure whether collecting parts would achieve much else in terms of story or gameplay? A two-way radio would be a massive upgrade, and it doesn’t make sense to me if you can just “upgrade” it by collecting a random collection of radio parts across North Africa (though I’m not familiar with how radios work). So far, lack of tank maintenance or paying attention to the radio hasn’t had an effect on my playthroughs, so I’m tempted to ignore it for other things (especially interacting with other characters). If there were more consequences keeping up maintenance and keeping the radio in trim would incentivise more player attention.
If the PC got a field promotion and ended up commanding multiple tanks I could see it coming in useful. However so far, especially with so much action being devoted to being unaccompanied by other tanks, it doesn’t seem important - you can’t communicate with the infantry (I think), so the radio’s useless much of the time.
Regarding upgrades, I’m not too sure about molotovs – grenades seem somewhat more practical and it’s said the PC doesn’t want them in the tank either. Perhaps some sort of satchel charge, which might be less of a hazard since there’s nothing for it to catch on? Still think smoke grenades/projectors would be a bit more useful.
Regarding shotguns, my first thought is the M30 Luftwaffe Drilling (which I guess you could get from the Luftwaffe bomber), but it seems like a shame to cut that up.
A related idea for personal defence would be a machine pistol carbine – namely some sort of fully-automatic C96 variant, be it a Schnellfeuer or one of the Spanish versions. The Schnellfeuer would probably be taken off a dead German officer. I guess the Spanish versions could come via Spanish Civil War veterans (be they Axis or Spanish Republicans), so it could be taken off the battlefield or obtained by gambling. There is the Thompson, admittedly, but it’s a bit, well, bigger.
An idea which in reality would be quite impractical would be to stick a rocket on the side of the turret, whether it be a bazooka a la “Rosie the Rocketer” or a bazooka jeep, or something bigger like stealing the RP-3 from the Brits. It’ll see some attempted ground use in the Sherman Tulip later in the war. The Canadians tried mounting it on a Staghound, so an M3 makes some sense, I guess? It’ll be horrendously inaccurate but it’ll probably scare the hell out of anyone on the receiving end. Article on the Staghound Tulip and the Tulip’s efficacy.
Edit: Found the Staghound Tulip:
Canadian Staghound Tulip
Land Mattress Tulip:
There’s also the practice of welding spare tracks (among other things, ranging from planks to sandbags) onto the tank as a sort of improvised armour. Not sure if it was actually useful, and I think it was largely a measure against infantry AT rather than other tanks. Though, given the encounter with the anti-tank team and the Vichy French trying to mount the tank:
Sandbag armour Stuart with tracks welded to the turret(?)
But they could go perhaps a bit over the top:
Sherman with a lot of improvised track armour