IIS Redirect non-www to www AND http to https
Yes you can merge them into one and use the logicalGrouping for the conditions and set it to Any which would be the equivalent of an "OR". For example:
<rule name="Force WWW and SSL" enabled="true" stopProcessing="true">
<match url="(.*)" />
<conditions logicalGrouping="MatchAny">
<add input="{HTTP_HOST}" pattern="^[^www]" />
<add input="{HTTPS}" pattern="off" />
</conditions>
<action type="Redirect" url="https://www.zzz.com/{R:1}" appendQueryString="true" redirectType="Permanent" />
</rule>