Yes, although I will say that the piling up of consonants does produce some sort of sonic jumble that isn't quite a pure clean single syllable.
I can say "One! Two! Three! Four!" in a fast, rhythmic cadence, but "Strength! Strength! Strength! Strength!" is a bit of a tongue-twister. I can't imagine a crowd at a rally chanting it.
It's not unusual for people to pronounce it more like "strenth" if they are speaking quickly and casually, and if you say it clearly and carefully, I think there's a hint of a schwa sound after the "g."
As a matter of fact, I see that ahdictionary.org considers it to be one syllable but shows no less than three pronunciations: strĕngkth, strĕngth, strĕnth. The first is what I called the "clear, careful" pronunciation, and the third is the "casual" pronunciation!