Ci talk:1008488145
1) 猛醒 very rarely means "suddenly wake up (from sleep)". It's almost always "suddenly awake to (the truth)" (to quote New Century). One example where it does mean "wake from sleep" is 猛醒的睡狮.
2) 猛省 probably is never correct for the "suddenly wake from sleep" sense, because "wake from sleep" is not one of 省's meanings. For example, there are 17,500 Google results for 猛醒的睡狮, but zero results for 猛省的睡狮. You don't talk about sleeping lions suddenly coming to some realization.