Charcoal, 16 bytes

Ｗ¬›×⌊θＬθ¹⊞υ⊟θＩＬυ 

Try it online! Link is to verbose version of code. Requires input sorted in descending order. Explanation:

Ｗ¬›×⌊θＬθ¹ 

While a (last) crowd member's threshold is not too high...

⊞υ⊟θ 

... move the member from the crowd to the helper pool.

ＩＬυ 

Print the final size of the helper pool.