Looking on the internet deeply has found these results:

assign to him is the most popular phrase on the web.

assign him 1331,000 results on the web	assign to him 1407,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Where the consignor/exporter does not have an EORI number, the customs administration may assign him an ad hoc number for the declaration concerned.; Well, that's going to be a problem with just about everything we assign him to. So we thought you could assign him a case to keep him busy. I would be very grateful to you if you would assign him some duty. Did you assign him a sitter or at least ask one of your fellow residents to look after him? The emergency laws let you assign him to the barracks. So we thought you could assign him a case to keep him busy. I'll assign him to you, Mr. Myers.	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

assign him

1331,000 results on the web

assign to him

1407,000 results on the web

More popular!

Where the consignor/exporter does not have an EORI number, the customs administration may assign him an ad hoc number for the declaration concerned.;
Well, that's going to be a problem with just about everything we assign him to.
So we thought you could assign him a case to keep him busy.
I would be very grateful to you if you would assign him some duty.
Did you assign him a sitter or at least ask one of your fellow residents to look after him?
The emergency laws let you assign him to the barracks.
So we thought you could assign him a case to keep him busy.
I'll assign him to you, Mr. Myers.

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.