I thought the same as well, but then I figured, what does teampower really have to do with it? I have a way lower TP than anyone I ever encounter in the raids, but so what? I win some, lose some and stay more or less where I am, for some reason my TP is just lower than everybody elses… Clearly other factors are more important than TP.
Guess I am simply the better player, or at least I keep telling myself that
Wins on defense might have to do with the fact that my team 1. Looks super weak, so people don´t bother planning and just hit it with whatever they last used and 2. Is apparently quite different (no 5 stars, they are to bothersome to upgrade lol) and therefore same team doesn´t work. Obviously this won´t ever get me anywhere close to the top of the game, but I bounce around comfortably in platinum league and occasionally after a good run I open a diamond box.
My attack TP is usually around 3.8 to 4k. I never get anyone that small, usually they are 4.4k to 4.8k on rare occasions a bit below or above that.
I don´t look much at their TP(or colours for that matter), but mostly how much I lose for losing (or win for winning) and what type of heroes they have. If I only lose 10 for a loss I can lose twice and win on the third and still come out ahead. And there are few team I cannot beat in 3 tries, but even if it happens i only lose 30. Next fight I win 50 on a first try and I´m back in the game
But really raids are just a timekiller for me when I have nothing else to do… I don´t do them every day.
Long story short: TP isn´t important, matching against people within the same cup range makes sense as it matches people with similar ambition level against each other. If they do it with voodoo or skills or brute force, who cares?
It´s basically a performance index rather than an arbitrary number that depends on hitpoints (or whatever TP is based on).