One under the belly and 4 under the wing for 5 on the F.

The IL2 as a single unit being effective is quite debatable. In the numbers they were produced in any plane would be effective. The thousand plus Spitfires IX's at any time in the 2nd TAF used as ground attack aircraft were very effective.

Given the number of losses the IL2 suffered was it really the most effective ground attack aircraft pound for pound? I would say given the numbers produced vs losses there are allot more effective aircraft than the IL2. If I was charged with going to blow a ground target up I'd pick at least a dozen different aircraft before I'd choose the IL2.

Unluckily, comparison in the book was made between these four airplanes, with a little bit of Hs129 mentioning

It does not, because there were no Typhoons or P47s on the EF

I voted for the Fw-190, mainly because of it's greater flexibility plus the higher bombload and ability to defend itself.

Even the ground attack versions were still good fighters but could also be used as dive bomber/fighter bomber with a decent bombload. Especially it could carry heavy bombs other than the Il-2. Planes like the Sturmovik might be perfectly adapted to their niche but you need specialized planes for each mission, while good fighter bombers can be used in almost any role where they are currently needed most. You can achieve more with less planes, concentrate production and supply chain on less different types. A more efficient contribution to the war effort.

I disagree with that idea, it's an accountant's view, but if you don't have considerable air superiority, it means making targets out of otherwise servicable fighters.
No offence intended, but why limit the question to only the Eastern Front? Even so, there were, apparently, lend lease P47s sent to Russia, and they are modelled in IL2 Forgotten Battles.

effective: n adjective, producing a desired or intended result.

i am the only one that voted for the stuka so far :)

the stuka was purpose built to be a ground attack aircraft with a specific objective in that strategy, the pinpoint bombing of ground targets. as such it was extremely effective and without it the fast moving sweeps that the german armored units did would have been much less effective, maybe even impossible. but the stuka was dependent on air cover by its own german airforce, and without air dominance it was extremely vulnerable, such as during BoB when the english pilots had "stuka parties" which was like shooting fish in a barrel.

since your question asks about GA in the plural, you'd have to include the il2. again purpose built as a GA aircraft, but rather then pinpoint bombing its role was as a more general GA aircraft that was aimed at dealing with armoured vehicles or enemy targets that had light AA protection. with its very heavy defensive armor and several large caliber tank-killing forward firing guns, resulting in a "flying tank" aircraft that was good at both tasks. but being slow and heavy, it was also very dependent on appropriate aircover, and without it it wouldnt have lasted long. many of the high scoring german aces on the eastern front obtained their high scores by shooting down vulnerable aircraft like the il2 (until it got a rear gunner in its later versions, and by which time aerial forces btw germany and russia were fairly equal)

both those aircraft were good at what they were intended for, but had a somewhat different purpose. so if you ask "which is more effective", you'd have to specify as what because air to ground has different aspects, and each of those aircraft was good/better/best at some of those functions. the modern version of the il2 is probably something like the A-10, and the modern version of the stuka is probably a laser guided bomb that can fly down the chimney of a specific building :)

both the FW-190 and "any soviet fighter" are excluded from this question because they were not the major planes used in a GA role and were not built for that purpose (obviously variants existed that had that capability, and modifications were made at certain times so they could be used in a air to ground role).

Because, as I written in the initial post I'm making an article about one book, which describes SU and Ge ground attack airplanes. And I have to say that so far the people on the forum had shown more common sence or knowlege of history then the authors.
P47s were never used as GA airplanes on EF, and I'm not talking about a game, but about RL.

Wasn't The 190 the official successor of the stuka ?

HS 129 and Ju 88P-1 replaced the Stuka where possible.

FW190 was more a fighter/bomber