IIRC, without emergency redeploying, they might have issue running less than 4 - not sure if the tag server can coexist with web server anymore for example, red

IIRC, without emergency redeploying, they might have issue running less than 4 - not sure if the tag server can coexist with web server anymore for example, redis is still a dependency, so is haproxy, separated SQL and IIS, etc. Then there's support services (iirc, all of elasticsearch was non-functional requirements stuff and technically could be run without?) and HA.