For incoming calls Twilio uses different IP addresses, so, when using SIP you must create one trunk for each of these IPs. When using PJSIP, you only need to define the IP addresses with the CIDR in the match field, so, with PJSIP you will need only one trunk.
Here’s the link with the origination IP addresses of Twilio:
https://www.twilio.com/docs/sip-trunking#ip-addresses
