every Jack has his Jill; there is a lid for every pot
Proverb meaning that no matter how flawed a person may seem, there is a compatible partner for them. Literally 'a mended lid for a cracked pot'.
As the saying goes, 'every Jack has his Jill,' so I'm sure he'll find a good partner too.
あの二人はお互いに欠点があるけど、まさに割れ鍋に綴じ蓋だね。
Those two both have their flaws, but they're really a perfect match—like a mended lid for a cracked pot.