Those qualities don't matter much when you are faced with impossible odds. Wasn't he winning the civil war before the landsmeet started?
The Civil War is the problem. Loghain initiated one based on the extremely flawed premise that Orlais, rather than the darkspawn, was the biggest threat to Ferelden. His strategy from start to finish was an exercise in failure, and one that nearly caused the annihilation of his country.
I haven't read the books so I'm not well versed on whether or not Loghain executed a brillitant strategic plan in the war against Orlais, or whether he (rather than Maric) deserves the credit. So I'm just assuming that Loghain did execute a brilliant, or at least good, strategic plan in pushing out the Orlesians. Working on that assumption it then gives Loghain one great or good strategic performance and one horrid performance. The summation of his entire career as a strategist then would be one of overall mediocrity.
*If* my assumption regarding the war of Orlais is incorrect however, and either there was nothing particular brilliant about Loghain's strategic plans or it was Maric that was responsible for Ferelden's grand strategy, then Loghain's ranking as a strategist would have to come down from mediocre to terrible.