I don't understand. Let's assume that the blue army is **1** such that, when attacking without reinforcements, the red army wins the battle with a 99% loss of its army, and when attacking with reinforcements, it loses 10%. The reinforcements do not affect the losses of the defending side (100% in both cases). Can you attack with reinforcements?
I just had another example in mind – I attack, for example, with 131 units and 9 monks, built in the 2nd week. I get an implosion in them, and the opponent buys them off.
It turns out that the presence of reinforcements affected the losses – the monk reinforcements were lost. However, there is not much difference for the opponent, except that they have a wider choice – who to eliminate.
Added 13 minutes later
To avoid getting into bureaucratic details, I rephrased it – it is generally impossible to attack with reinforcements, even on weak units. It's already too difficult for the red side.
I made changes to the rules; thank you for the correction.