From zdic, 强横 means "brutal and unreasonable", which does make sense. However, at the end of the line, it also adds "describes a person like that".
But if it is used as a description for something like strength which isn't something that is living, how would it make sense then? I mean, how can "strength" be "unreasonable"?
If that doesn't work, would something like "overwhelmingly strong" work as well?
EDIT: Somewhat related, but does 強橫 always have a negative implication, similar to perhaps "savage" or "uncontrolled" rather than a neutral "strong"?