The Allied commanders were less bold for a very simple reason. Western democracies cared about casualty lists in combat, the Russians didn't. The western allies attempted to minimize casualites on their side, which made them appear somewhat indecisive.

The Soviets simply didn't care ... there was a quote of Zhukov's (I think, it could have been Konev, though): 'If my infantry runs into a mine-field, I want them to march over it like it wasn't there.' Hardly an attitued a western commander would have had.

And that attitude won the war.

Interesting tidbit ... the USA provided trucks for what would become the famed Katyusha. The words USA were stenciled on the truck above the white star. The Soviets repainted the star red, but the letters remained (they didn't have that much time), so the common agreeance among the soldiers was that the letters stood for: to kill that son-of-a-bitch Adolf.