I see different forwarders count using the following different ways:
So, which one should I guarantee and is there any better way?
From the MC run the below - it should give you a starting point
index=_internal source=*metrics.log group=tcpin_connections fwdType=uf hostname=* | eval hostname=lower(hostname)
| fields _time hostname sourceIp arch destPort fwdType os ssl version
| table _time hostname sourceIp arch destPort fwdType os ssl version
| dedup hostname