US cluster bombs lead to higher Ukrainian attrition rates

In war there's a proportionality; Especially when there are "vicious weapons" deployed. First usage is responded too with the same level of violence since it's proportional. However, when US cluster munitions were deployed and used by the Ukrainian side in this war; It's target could be (officially) mainly entrenched Russian forces; And now with (according to some) the fielding of Russian cluster munitions the balance in "viciousness" is reset but the result couldn't be imagined; This since Russian cluster munitions will fall on advancing and mainly dismounted regular infantry solders. Resulting in more casualties then when used against entrenched solders who can hide in bunkers. In this the US Biden administration not only miscalculated the effect of using "viscous weapons"; But didn't anticipate a proportional response by the Russian side increasing attrition rates for their own proxy solders in the Ukrainian armed forces. Or they just didn't care.