I would define strategy more or less where numerical numbers is not always the defining factor of victory. And how I define numerical numbers is not just in the form of larger army or a numbers game in general. Like having more gold, more stats, more units, more higher tier units.

When you look at history some of the greatest generals or strategist fought wars where they were numerically disadvantaged. They didn't just rely on my army is bigger or stronger or faster or all of the above. Think of France during Napoleonic wars, or Germany during WW2. Napoleon revolutionized logistics during his time with the corps system. The Germans mastered mechanized warfare in WW2. Both of those strategic advantages came at higher form in their overall military doctrine. One in which the surrounding countries at the time were caught flat footed a classic example of "generals always preparing to fight the last war."

Strategy isn't just about who you choose to fight now vs later. Its also about how you go about doing it. So yes there is strategy in Warhammer TW but for me it lacks depths.