PCs want to ambush a somewhat fortified position and I'm a bit worried.

My 4 players (level 7) stumbled upon a kobold being chased and harrassed by some hobgoblins riding on worgs. They save him and learn, that the kobolds village was raided by hobgoblins. They also learn, that there are 18 hobgoblins.

So, the village is located between some cliffs with 1 entrance. the village itself is a bit cramped, since there are 1 hobgoblin warlord, 6 hobgoblin captains, 12 hobgoblins, 6 worgs and ~30 frightened kobolds (including children).

the hobgoblins will act tactically and might hold the kobolds hostage to get out if the fight goes poorly for them. they are smart. in the past my players defeated a 100 orc raid and defended a town, so they might have too much confidence.

do you guys have any tipps? because if the hobgoblins fight smart, the pcs will surely die, though they are decked in magical equipment. I thought, that at some point the kobolds could revolt, but I'm still a bit worried, that this could be too hard.

edit: pcs are already at the entrance and alarm is being raised.