POE 2 has a nice little mode called frontline. Each side has an uncap base (or you could have cappable), and you can only capture a flag if it connects to your one. Since all the flags are in a line, this forces people to all go for one flag. This mode is great for smaller numbers of players.

e.g:

red uncap - red base - red base - red base - [neutral] - blue base - uncap

Here red are winning. Both sides can only go for the neutral base right now.

e.g 2:

red uncap - red base - red base - [red base - blue base] - blue base - uncap

Now either team can only attack the other base in square brackets, as there are no neutrals. They can still go round, but only to attack from behind.

P.S: The map I played this in had lots of open space punctuated by buildings - this wouldnt work in city maps, as Karkand (which is essentially an example of this) shows well.