Politifact checks Capitol police rumors

According to them:

"We have not seen evidence that Capitol Police granted rioters access to the building or that they were 'in on' the breach, as some posts claim." But they also noted that 

"The agency has a force of 2,060 armed officers and operates with a budget of over $460 million. It has armored vehicles. They can deal with incoming aircraft." 

So while the police force on the ground couldn't handle it, that still doesn't answer why, with 2,060 officers at its disposal, weren't more or all of the officers on the ground when they knew something like this was coming?