I personally play better on a 9 foot table than on a 7 foot table, but the reasoning I believe has more to do with my cue ball control, speed, and positioning rather than my ability to pocket balls. I find running out on a 7 foot table slightly harder for me. The reason is there is more traffic to deal with, if I get out of line on a 9 foot table, I am rarely hooked, and since I can pocket balls with perfect aim, it doesn't matter how far out of position I end up.
I think this is the same thing you were saying or trying to say, but if somebody plays better on a bar table (for their relative skill level) it almost has to be either because their ball pocketing is a particular weakness, or because one or more of their position play (including speed control), patterns, and strategy are a particular strength.
Vice versa if you play better on a 9 ft for your relative skill level than you do on a bar table which would indicate that either shot making is a particular strength, or one or more of position play (including speed control), patterns, and strategy are a particular weakness.