Up front: NEVER take any politicians by his word (let the media insist on doing such nonsense).

ON the other hand: haven't heard Zelensky talking about casualty rates of 600 a day. AFAIK, he was talking about 100 a day, without…

Up front: NEVER take any politicians by his word (let the media insist on doing such nonsense). The mass of them is speaking in hyperboles.

ON the other hand: haven't heard Zelensky talking about casualty rates of 600 a day. AFAIK, he was talking about 100 a day, without specifying if this is just KIA, or KIA, MIA and WIA.

Anyway, yes: there are entire companies of the Ukrainian Army that have been de-facto destroyed while slowing down the Russian advance, the last two weeks.

That said, the Ukrainians are constantly rotating elements of their units in and out of the frontline. On average, every battalion has one or two company/ies up front for three days; the other two (or more: some of Ukrainian brigades have battalions with 5, 6, even more companies, nowadays), are getting rested. It's only in the case of emergency that all are sent to the frontline.

So, if one is unlucky, and assigned to the company serving its three days in the frontline when the main Russiian blow comes in.... well, one can easily find himself killed, wounded, or captured - and versa vice: people from the same battalion might survive without firing a single bullet, just because they were having their day off.

One way or the other, battalions remain intact, even if losing a company (or, sometimes, and tragically: two).