Normally, you don't want to do spear rushes against English because their villagers just sort of shoot you, right?

Against English 2TC play, Mongols can produce a few Keshik to force the King away and then fully invest into a trade boom.

Against English spears, Mongols should probably just upgrade Keshik rather than switch into archers.

You're not going to Spearman Rush English. The reasoning is that you save a lot of stone from your Ovoo that you're not putting into Spearmen, so instead as soon as the Age comes through you're able to double produce a lot of archers. And English are not able to immediately full-on blast archers out of the Council Hall; there's going to be a little bit of down time with the income.

Of all the civs you could build Mangudai against, English is possibly the worst one. English can counter Mangudai with the bonus armor on the Men-at-Arms, and in Feudal Age just having Longbows with +2 range means you can take them down from afar.