1) free-online-resources tag (has just one question) can be merged to online-resources. 2) resources tag and resource-request tag be merged or have their tag wiki better defined and differentiated? 3) what about potential tags which are used rarely like 'mooc'
If a tag has just one question, and it is very similar to another tag that has many questions, I recommend just deleting the used-once tag. When searching, for example, one can always search for "[online-resources] free" to scratch that itch.
Looking at the questions, I think [resources] and [resource-request] can be merged.
If the concepts behind them are sufficiently unique and well-defined, I prefer to let them be as they are.