While this is sometimes true, it’s important to remember that there are several inter-related resource pools that each player is maintaining:
- Hand
- Gold
- Workers
- Board (including the sub-pool of patrolling HP/armor, and the overlapping sub-pool of heroes to unlock spells, which itself has the sub-pool of levels, which can potentially unlock ultimates)
- Tech buildings (which are technically on the board, but separate enough that I think of them as their own things)
Often shoving creatures in the patrol zone gives the opponent just as much to think about as hitting with a hasted creature or a spell.
Consider: I’m at 3 cards in hand at the end of my turn. If I worker and play one card next turn, I’ll still be at 3 cards in hand. If you’re at 5 cards, I’m at a significant disadvantage, because I’m slower to cycle in my new (better, or more optimally answering, techs). I’m also at a significant disadvantage because I have fewer options each turn to address the threats presented on your turn, and I have a higher chance of drawing a very weak or dead hand.
So I patrol in technician.
You, on your turn, might not want to do the mathematically optimal offensive play if you decide that that keeping my hand resource starving is more important than starving my board resource. You may then decide to build up (level heroes, build tech buildings) instead of keeping the board pressure on. Or you could decide to keep the board pressure on, but you know that it risks me drawing into answers and coming back to equal footing more quickly. You face the same problem anytime I put something in scavenger.
It’s not always an obvious choice. Sometimes killing a technician will cause a deck cycle, giving the opponent a chance to draw a really nasty threat.
It’s almost always correct to break Tech buildings if you have the opportunity, but sometimes it’s more important to take out a hero. Sometimes it’s more important to keep the opponent’s hand or money low so that they are unlikely to be able to do much even with their fancy Tech II, and if they manage to, their hand goes down even further.
It can sometimes be really hard to tell whether an opponent put a unit or hero in technician because it’s valuable and they want some compensation if they can’t have it, or because it’s not valuable to their plan, and it’s bait, and they really need to draw a specific card on their next turn. Figuring out which it is can be crucial.
Oh, one last thing: because of the fog of war, you often don’t have to add spells and haste to your deck as defender; they just have to be in your codex. Since the opponent doesn’t know what you teched, they often have to assume that spells and haste are possibilities, and try to play around them.