In your opinion, which faction is the strongest in Heroes 5? Let's discuss the advantages and disadvantages of each faction.

I don't even plan to protest, but any reasonably decent opponent won't let you level up to 60 knowledge. At best, to 30, and even that's a lot. Normally, 20 is enough... The Necromancer, by the way, is less dependent on the map, but also less dependent on randomness in general. His tactic of "making a huge number of troops" is effective to some extent, because there are no large maps with a small number of neutrals, and also without additional cities; at least, the random map generator doesn't produce such maps, these are already some kind of fantasies. The Necromancer is good on small maps, good on large maps, and not so dependent on resources; he is consistent in all respects. Only on large maps without additional cities is he just decent, but with additional cities, he becomes a very serious opponent that not every faction can defeat.

If we agree that you can attack after three or four months of the game, or even more... In my opinion, I can only assess the strength of a race at its maximum level of development and using all its possibilities; here, I repeat, mages beat everyone...

No, the strength of a race is assessed by the number of victories with it in games when there are no agreements (except perhaps for the rules of online games, which are made to create some additional balance, so they can be understood). People should play to win, not for ambition, then it will be clear which faction is strong in what. But these agreements... With the same success, you can agree to use only chaos magic and buy armies exclusively of the third level, no more, no less. This is so that mages definitely win, with alt-gray golems against chaos. And come up with something else... But there is little point in these agreements.

Of the normal archers, only Battle Mages, who should be replaced with Fire Mages in the early stages.

By the way, I wouldn't replace them. Fireball is a fireball, but archers need to be covered by someone, and archmages cannot be covered; they will shoot at their own (they won't throw fireballs all the time).