I think Zhukov had very little to do with the initial defeats. The forward deployments in the newly seized Polish territories had numerous reasons, and Zhukov certainly wasn't about to attack into German territory. Current Soviet doctrine at the time emphasised that any conflict should be fought on foreign land however, so the immediate goals in the event of war was to counter-attack into the German territory. This was pretty much the reason for the deployment, not any particular fault of Zhukov.

Regarding the obsolete Soviet tanks. Most Soviet tanks weren't more obsolete than, say, the German PzKpfw-II and PzKpfw-35. Really, the main reasons the Soviets lost so many were that they lacked support facilities, ie they broke down, ran out of fuel, never started in the first place, never were issued ammo, etc. All of this compunded by Stukas blowing up dumps and such, of course. I'd say the biggest fault quality-wise was lacking radios.

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"Nervous wait for the whistle to blow
Rush of blood and over we go..."
- Iron Maiden, "Paschendale"