"Persons" (that is, the plural form) is not generally used in English except in legal forms. You might see a sign in an elevator, for example, that says "Maximum occupancy: 11 persons," but otherwise you'd usually refer to one person, two people, and so on.
"They sent us two people" is past tense. The German sentence is present tense.
Can this just be seen as the polite form? As in "Yes, you send us 2 people?"
The English in their answer above is correct. To me DL suggested "they send us two people" which is not correct English. (Englisch ist nicht meine muttersprache)
"They send us two people" is also correct, but the meaning is just a little different.
"They are sending us two people" means that right now, they are in the process of getting two people to us.
"They send us two people" might be used in a context in which a routine is established: for example, "We have a problem like this about once a month. We call technical support. They send us two people."
US Englisch Muttersprachler