You should use the collector/input based on the needs and not the number of servers you have. Files are easiest taken with the filebeat, windows event log with the winlogbeat. If you want to collect network equipment logs syslog would be a better solution. Maybe syslog might be the best choice for your Linux server logs too.
Personal I would go with one input for each type using processing pipelines to process the logs. If you take the extractors to work with the data it might be easier to work with several inputs one for each type.