Posts from Orcs. Upgrade or alternative upgrade?

Yeah, right. What's the difference between attacking without a penalty or retreating and shooting?

Level 1
Depends on the opponent. If they are a mage and the number of Goblins allows for effectively blocking them, then I choose Sorcerers. They are also chosen if the opponent intends to fight defensively.
Trappers are chosen much less often, for example, if the enemy is Inferno or Dark Elves. Setting a trap for Furies is a sacred duty for every trapper (besides, of course, being fed to a Cyclops, sacrificed to Shamans, or flying into the enemy ranks instead of a projectile with a loud cry).

Level 2.

Most often - War Centaurs. They are healthier, have slightly better defense, and effectively kick with their hooves, while maneuvering is a rather questionable skill, especially in the final battle.
I choose Nomads in exceptional cases, for example, at the very beginning of the game if the main hero is not Haggeesh, or for a secondary hero.

Level 3.

Most often - Warlords. I think everything is clear here.

Level 4.
Daughters of Earth. Stronger, healthier, faster, and do not take damage from a slowed-down opponent. In general, I choose them in 99% of cases.

Level 5.

It's hard to say. Most often - Leaders, due to their ability to shout at their subordinates, accelerating their turn. I use them in battles where I need to quickly shoot down enemy archers with Centaurs. What is also important is that they increase the Initiative of all nearby units, so sometimes, if the enemy thinks they have too few arrows, you can also rush at them with a Goblin.
Executioners are a very tempting option, probably depending on the situation. If the skills and found artifacts allow, they can be the first to break into the enemy ranks, crushing everything in their path and scaring everyone with their brutal appearance and, obviously, smell.

Level 6.

It is very difficult to say, because I usually build them last. Due to their high cost, they often do not pay off, but if it comes to that, then probably Pao-kai in a long game and Dark Wyverns in not very long games.

Level 7.

Most often - Bloodeyes. Slightly healthier and, most importantly, faster. Under certain conditions (more precisely, if at least 2 out of 3 possible conditions are met - Boots of Speed, Tactics, and Speed Aura), they can reach the enemy ranks on their first turn and cause a lot of trouble.

Free Cyclops are, of course, sometimes more tempting: they hit so hard that everyone runs for their lives. However, their speed is slightly lower, and they can kill more of their own than enemies. If you do choose him, then place him far from the rest of the army and only release him on a cluster of enemy stacks. Otherwise, I don't think there is any point in choosing this upgrade.