I’m guessing that with experience points you mean Battle Power (or BP for short).
BP isn’t a great indication of how strong a team is, because it doesn’t take into account things such as synergies between your own dragons or the weaknesses your dragons have against the enemy dragon’s abilities.
More Concrete examples:
Take for example a team that has the following dragons on it: Skywarden, Toothless, Tricky 2 heads, Revenger and SoS. At first this team might look really nice, but when you go and take a look at their abilities you’ll see that a lot of them have the same type of things.
- Toothless, Skywarden and Revenger All buff the other dragons with spirit gen up.
- Tricky 2 heads, Revenger and Skywarden give all allies Counterattack
This overlap between them isn’t great, because the same type of abilities don’t stack (they just overwrite the previous ones). And normally you don’t need to have more than 1 dragon that gives you a certain ability (if their spirit speed is moderate or faster), since they’ll generally charge up fast enough to make sure the buff/debuff is active on your dragons at all times. So having multiple dragons that do the same thing makes you “waste” parts of their abilities. Now BP does not take this type of thing into account. So if you were to have 2 teams, one of which has a lot of overlap between abilities like the one I mentioned and one that avoids having such overlap the latter will be much more powerful even though BP would make you think they’d have the same strength.
And the second thing that BP doesn’t take into account is countering abilities. For example if the enemy dragons are those that heal themselves or their allies, you could take a dragon with you that prevents them from doing so (the heal block debuff that dragons such as murmurquill apply). The enemy dragons would then be a lot less difficult to defeat, but BP won’t show you that.