The higher in rank a team is the more points you get, so if a player has like 300 more points than you you'll get like 25(+0-10 depending on how long your streak has been going). The game never gives you teams with WAY more points than you have so you have to just keep refreshing until you get someone with a decent amount of points to take down. A team with 3 level 1 characters can still earn you more points than a fully pimped out 6*/60 team, look at how many more points than you they have.
On revenge: If other players challenge your team, it'll come up in the defend tab(same screen that gives you your ranking info). When it says "defeated" that means that a team has defeated you, if this happens you get a chance to take revenge and earn more points(5 times a day max). Because you only get 10 matches a day, using a bait team(a team strong enough to win fights but weak enough to get beaten by teams that your main team can handle) is a good way to also get 5 revenge matches in a day, if you're confident you can revenge any team that beat your main team then that's fine too.
Sadly, because you can refresh your 10 matches with crystals, whales will ALWAYS land on top of the rankings because they can simply play more matches than anyone else.
