When creating SPF records, you must only create one per domain as per RFC 7208 which states the below in section 3:
"multiple SPF records are not permitted for the same owner name"
Read RFC 7208 here: https://tools.ietf.org/html/rfc7208#section-3.
If you have more than one server that sends email for a particular domain, you should merge the IPs into a single SPF record and not create more than one record.
For more information on SPF records, see my two part article here.