Losses? There are none. I complete every map without losses on neutral creatures.

This indicates that you are attacking too weak neutral creatures and too late. In Multiplayer, time is of the essence; whoever acts faster wins. A heavy push with losses is inevitable. For example, is it better to lose 1 day of tempo by waiting for reinforcements, or to break through an important passage now, but lose 50 goblins? And what if an opponent rushes into the same zone to grab the most powerful artifacts? 50 goblins are nothing. You constantly have to solve such problems. Speed comes at a price.
In single-player, which is designed for efficient gameplay (speed), the same applies.

Added 6 minutes later

what perks will remain in "Offense"?

Ranged attack, tactics, speed, ballistics, series of hero attacks (devilish, stunning, weakening)
I used to think about forest fury and hirdu, but it turns out these perks only work on racial units. I will probably have to replace them with cold steel and fire fury (for +10% fire and ice damage).

Added 8 minutes later

without perks :) - a good comparison of skills.

Exactly - without perks. Because the criticism is directed at the skill itself, not at the skill + perk branch. The balance between skill and perk is being discussed, when you get everything for a perk, but nothing for a skill.

The current Offense skill is strong as a whole. In 2 levels, we get ballistics (which pays for itself) and +5% from the "buy a product for 100 and get 1 ruble in change" series. Then, in another 2 levels, we get retribution (up to +25% damage, including ranged) and again +5% in change. And finally, in another 2 levels, +30% initiative (for 8 mana and spending 50% of the hero's turn) and the same 5% in change.