I actually liked that in the fourth installment, unlike the previous parts, you can move more freely around the battlefield, the units have drastically different sizes, and the terrain is uneven and hilly. Regarding calculations: firstly, when hovering over any part of the field, the number of turns required to reach that point is displayed. Secondly, you can also see the turns of the enemy unit by right-clicking on it. Thirdly, you can enable the combat grid, which clearly shows where a unit can fit and where it cannot. Furthermore, the retaliatory strike is restored after a full turn, i.e., if there are 14 units on the field, and your unit has used its retaliatory strike, it will reappear after all 14 units have taken their turns. A log is certainly lacking, but you can still manage without it, knowing that units with higher initiative go first, and it's not difficult to remember who has gone and who hasn't.
Practical example: you need to calculate what area a unit will control if it moves to a specific point. In Heroes 4, this simple action is very time-consuming, so you have to rely on guesswork, and every mistake can lead to a major failure (loss of a turn).
Many units have significantly different damage values, to the point where the minimum is three times less than the maximum, so it's not even close to 1:5. Moreover, attack, defense, and speed also play a big role; for example, 60 rogues, with a total health of 600 and damage of 60-180, cannot cope with a single black dragon, which has 400 health and 55-110 damage.
It's precisely with those random units that you mentioned that you can see: the black dragon has stats of 40/40, damage to hit points = 82.5/400 = 20% (approximately). Rogues: stats 9/9, damage to hit points 2/10 = 20%. Why, for example, couldn't they have made the rogues more interesting, for example, with damage of 3-5 or 2-6 per 10 hit points? Especially since this is a unit without combat abilities, and its physical stats are standard.
And the so-called assessment of the battle "by eye" exists in almost any tactical game, even in chess; it's just that in the fourth installment, it's more difficult to think everything through perfectly.
As in any game, a novice cannot simply take and play without problems on the highest difficulty. You need to learn how to break through large armies of neutrals with minimal losses, and this takes time.
Chests and various buildings that give experience for free help with this. And if there are none on the map, it's not the game's fault, but the map creator's.
But everything else can be built quickly and without particular problems on the highest difficulty if you learn to do everything correctly.