Yes, the sword decreases in stats as your troops do. 100% positive, there is no doubts nor room for argument on this one people.
If it's a static bonus, then it stays the same as troops lower. However, percentage bonuses, like the Abyssl Blade, lower as your troops lower.
Eric are you sure? When I'm not at full troops the abyssal blade still says it is giving me the attack I have when I am full.
The value on the equipment page or on your profile does not change, however the stats from all your equipment are added to your raw stats. Those decrease as your troops/spies decrease, and so the overall effect decreases as you unload.