Rule of mentality

Is it a good rule of thumb to stick to these

his team is = to you = normal mentality
his team < you = attacking mentality
his team > you = defensive mentality

Now is this the right line of thought? Or should it be, attacking at home vs equal team for example.

Generally, yes, but you can still go normal or even attack him if he's stronger than you but you've countered him perfectly. It's not wrong to go defensive with counter attacks and long balls against an equal or weaker team as well.