No one generally argues with the correctness of investing in troops. It's just that some conclusions, such as: only losers spend money, and it's essential to buy many heroes for scouting (they will pay for themselves instantly), can be strongly debated (which, by the way, is happening).

I agree with Er@ser.

It's also important to consider the player's skill level. I'm sure that 80% of players, if given 8 heroes for free at the start, won't know what to do with them.
And not everyone will be able to effectively fight battles with an army in the first week.
So, the question is - why spend money on something you don't know how to use?

Before spending money on an army and heroes, you need to learn how to accurately assess the consequences of battles, build efficient chains of actions, clearly plan hero movements, and have certain tactical skills. Until then, it's more effective to invest in income. For 80% of players, the right first move is to build a Prefecture (1000 income).