If I take a Di ally (4309) and decide to take Chinese troops, is it correct that I don't need to take the otherwise compulsory foot crossbow, as minima don't apply in allied contingents?

Just making sure before I do any purchasing!

Minima are halved.  They apply to allied contingents unless the army list specifically states otherwise.

Richard

For the Di list  there is the following note applicable to their Chinese troops:

Note:  Minimums apply to Chinese  troops if any Professional generals or Chinese troops are taken and do not apply to allied contingents.  They may only be used between 351 and 394 CE (Former Qin) or 386 to 403 CE (Later Liang)

So given that - do I still need the Chinese crossbowmen?

That is, if I do want to take some of the other Chinese foot in my ally.

Sorry - I should have read the correct list!  Apologies.

Because the note says you don't have to take Chinese troops in an allied contingent, then NO - you don't have to take the Chinese troops.
A Di ally will have to take a minimum of 9 infantry and 6 cavalry.

You can still take Chinese troops so you could (for example) take just one UG of Chinese crossbowmen, upgraded to Average Protected.  This is as long as the ally is Former Qin or Later Liang.  The ally can be either an Instinctive or a Professional general.

Richard

Sure Richard - I understand I don't have to take Chinese troops.

But if I do take the Chinese troops do I have to take the crossbow?

As the note says the minima do not apply to allied contingents can I just take the close fighters troops plus the minimum 9 foot and cavalry noted from the main part of the list?

Yes, you can just take the close fighters.  The wording says the minimums do not apply.

Richard