Again, Purges weren't about skill/initiative or even obedience. Purges were about factions infighting. Commanders weren't shot because they were too independent or showed too much initiative, people were shot because they were loyal to a wrong person or they were rivals with a right person. And both good and bad commanders can be such unlucky people.
The main problem of the Red Army was always education and amount of practical experience of the commanders. This is a main reason why soviet officers lacked "initiative" and were more reliant on detailed orders from above. It is very logical behavior in case of lacking experience - you just follow orders.
And this was main negative effect of Purge - it promoted even more people with insufficient experience for their posts.
For example we can name general Pavlov (who was shot for collapse of Western Front during WWII). He was damn good brigade commander and decent chief for soviet armoured force, but entire front was too much for him. He failed at this job and lost his life as the result.
Not sure about faction infighting since the only faction that benefited from purges was Voroshilov's one, him being virtually invulnerable. Everybody else simply tried to survive and protect whom they can. I mean, what was district commander (say Timoshenko) supposed to do when it is demanded of him to make a list of unloyal commanders? Buddenyi defended ex-White army corps commanders for example. Sure some took advantage of it, but everybody understood perfectly that it has to stop. Pavlov and Kulik (rather bad reputation of Stalin's crony) wrote a letter to Voroshilov in summer 1938 saying that purges take good officers.