Top cat can be determined by who defers to whom.
Who chases whom.
Who eats first.
Top cat may keep themselves up high. (high perch)

They may be playful, but they decide who and when to play, or they may be keep to themselves type, keeping the others in line.

I made the mistake of thinking the most active, playful cat must be top.
I called Snowy my Alpha-male, when he is really my laid-back male.
Mr. Jones is really in charge (when Malfi is not downstairs) but when Malfi comes around Mr. Jones defers to him.
Sort of a co-top cat situation.
They all know Malfi is kind of old.