Well damn. I was really excited for this before I realized the developer wasn't willing to actually make his Afrika Mod like the African Campaign. Isn't willing to make new vehicles? Isn't willing to incorporate period accurate weapons and classes? Isn't even willing to confer to a more experienced modder's opinion, one which seems to even be interested in contributing?
Look I'm going to tell you right now, if your going to do this, your going to need to do it right. That means your going to need to find someone experienced in making vehicles for RO2, which is very few people at this point for some reason. The African Front is famous for it's Tank combat, and the only heavy Infantry battled happened either later in Tunisia, or during the American Operation Torch. Your also going to need to accept that most people around here play RO, and RO2 because it IS historically accurate. Don't include an elite rifleman class, it's unfaithful to the setting your trying to replicate.
Also you seem to be missing the point that the Infantry engagments in Afrika were fought mainly with the Enfield vs the Kar, and the Bren vs the MG 32 at long range. That's how you can make your mod different from the other two, and give it it's own flavor. Focus on maps that actually incorporate TW's fantastic bullet physics. Simulate the rolling dunes of the desert to make best use of long distance engagements.
As for the discussion on the Sten, it was used, though sparingly, so incorporating it is fine in the same way TW incoporated the StG. I'd make it an alternative to the Squad leader's selection of either a Thompson, which is the same model used in RS, or the Enfield.
Furthermore, I'd base allied class selection more on the Americans, and of course keep the Germans more or less the same as in RO.
Allied - British 8th Army
Rifleman
M1917 Enfield
Webley Revolver / Colt M1911
Mills bombs
Engineer
M1917 Enfield / Sten
Satchel Charges
Mills bombs
Squad Leader
M1917 Enfield / Thompson 1928 / Sten
Smoke
Mills Bombs
Webley Revolver / Colt M1911
Machine Gunner
Bren
Webley Revolver / Colt M1911
Mills Bombs
AT Gunner
Boys AT-Rifle
Webley Revolver / Colt M1911
Mills Bombs
Sniper
M1917 Enfield Scoped
Webley Revolver / Colt M1911
Mills Bombs
Commander
M197 Enfield / Thompson 1928 / Sten
Smoke
Mills Bombs
Webley Revolver / Colt M1911
Binocs
Tank Commander
Tank Crewman
Axis - Afrika Corps
Rifleman
Kar98
Walther P38 / Luger
Model 24 Grenades
Assault
MP39/40 / Berreta SMG? (Cool, unique weapon to the front?)
Walther P38 / Luger
Model 24 Grenades
Squad Leader
MP39/40 / Berreta?
Smoke
Walther P38 / Luger
Model 24 Grenades
Machine Gunner
MG34 (and only the MG34, no MG42's please for the love of god!)
Walther P38 / Luger
Model 24 Grenades
Engineer
MP39/40 / Berreta? / Kar98
Satchel Charges
Model 24 Grenades
Sniper
Kar 98 Scoped
Walther P38 / Luger
Model 24 Grenades
Commander
MP39/40 / Berreta?
Smoke
Binocs
Walther P38 / Luger
Model 24 Grenades
Tank Commander
Tank Crewman
Axis lack an AT-Gunner because from what I know they didn't use them in the African Front much, if at all. Balance by making use of the German's assault class, and maybe giving them an extra engineer compared to the Allies.
Now onto the topic of tanks. This isn't an area I know a lot about, so I'll just list some tanks from each side I'd like to see, and that are concurrent with the setting. Stars next to them mean that they are Iconic to the African Front
Allies
Vickers Light Tank
Cruiser Mk I & Mk III
Crusader
Churchill
Valentine
M3 Stuart
M10 Wolverine
M3 Lee
Matilda II
Axis
Panzer I-IV (Though the IV was used less due to being out performed by the III)
Panzerjager I
Sorry there aren't more for the Germans... but their side was rather scarce during the African Campaigns.