Dear K,
When any of the various 4 modern English language "sources" re-tell the little "truth" from Radetzky, they don't even render it very well. For example, there is no such thing in English or French as "maniere de tirailleur". The problem is, from a English-language gaming perspective, that anybody can easily get the wrong impression from just reading modern English-language secondary sources. "Rothenberg [or any of the others] cites the original documents", but he does not give the context, nor does he even reprint the original German text. Yet, what else will the English-language gamer or rules-writer have to go on?
You say that "[Radetzky's comment] appears as a stand-alone statement assessing the relative ability of the Austrian and Russian regular infantry in 1813". It is part of a draft order, for one force on one day. I have trouble seeing this as a "stand-alone statement". I see the statement as dependent on its context. This context includes the absence of Russian Army Jäger from the force in question, and the role of the Russian Grenadiers and Guards that were there as a reserve formation.
That said, I don't think we disagree all that much
.
1. I tend to agree with your noting the difference between (i) "petit guerre", border/patrol operations, battles of outposts, scouting, and (ii) the rôle of skirmishers in major battles. I would further note two additional rôles for light infantry in the "middle range" between the first two röles, namely (iii) the conduct of operations in open order where the terrain does not readily admit the use of formed troops (such as in towns) and (iv) the functions of multi-battalion advance and rear guards.
2. I would grant that Russian Jäger did not have the same rôle in offensive operations during major battles as the French skirmishers. Conversely, they were tougher in the defense. The 49th and 50th Jäger stayed engaged until essentially destroyed at Borodino – 50th Jäger had only 40 men left standing at the end of the day. These same two units had done much the same kind of work at Krasnyi in August. And again the 23rd Jäger at first Polotsk and 26th Jäger at second Polotsk. Back at Borodino, we can see similar endurance from the 1st Jäger and the "Finns" (Life-Guard Finlyandskiy regiment, a Guard jäger unit). And so on.
3. Looking at the other three listed rôles for light troops, I can't see any difference compared to the French. Hence, in games terms, I see them essentially as equal by 1812. I would not argue, in a tactical game, against some kind of +1 for French in open order attacking combined with other troops in a major battle
.. as long as I get a +1 for Russians defending.
4. I would agree that specialist infantry was a problem for many nations, and the French had a better approach. Although the specialization for the Russians was much less than for other Continental powers, there was still some "flavor" of it, even in 1812.
5. The key problem with specialization is, I agree with you, fielding enough of the specialists. Here I think the Russians lacked greatly in 1805, but did well in 1812-1814 : 59 regiments (177 battalions) of Army and Guard Jäger, supported by another 17 battalions of volunteer hunters and marksmen from north-western regions – better than a 1:2 ratio to Army Infantry battalions. Were all these units of equal quality? No, of course not. But the same holds true for the French.
While I am sure there are nuances and "points" where we disagree – this happens with reasonable men – overall I think we not so far apart in our conclusions.