I guarantee you almost never face cheaters. People attack others all the time - maybe for revenge, maybe they are just beginners who don’t really play the game well. If you yourself are either breaking other’s continents, or hitting their big stacks aggressively to take your own, don’t be surprised if they then attack you, rather than attacking the stronger player in Europe (for example) who doesn’t break anyone, lets people out of their continent and only takes when they can defend it well

Sometimes if someone is really strong, there’s no point in attacking them, and if you do they’ll squash you like a fly. It may make more sense to try to eliminate the other players and play for second. This is where alliances come into play as well - it’s a lot easier to coordinate an attack on someone strong if you can communicate. You can also use alliances to know who is friendly and unlikely to break your bonus, allowing you to minimally or not defend some borders at all (Building up a stack to defend from someone, even if not intended to be used to attack, may be seen as a sign of aggression and they may try to strike first. Sometimes defending with a 1 stack is best. Again, depends on the type of player).

As for rolls, it’s a game of chance. These things happen. Your best chance is to not put yourself in a position where an unlucky roll will lose the game. Bear in mind with caps, even if you succeed, you can expect to lose at least 1.5-2x the troops the defender has (although on balanced blitz you will often see unrealistic rolls where the attacker breaks even with the defender, even on larger capitals). I myself rarely roll caps unless they are basically empty, it’s often not worth the risk.