Both rhema and logos are translated into English as word.
So what's the difference and is it important.

Rhema embraces something contextual (i.e. relevant to a given situation, personal application).

Logos embraces the broader message (i.e. scripture, the Bible).

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I see rhema and logos working together something like this...

In Mark 16:17 we read "These signs will accompany (follow) those who believe ..."
Signs follow believers, believers don't follow signs.
Like a ship is followed by its wake on the ocean so signs follow those who believe.

A ship can only be steered when it is moving.
In faith we can leave the safety of the harbour and proceed within the boundaries set by the logos.
Once moving Jesus can adjust our direction with a rhema word (nudge) as necessary - again staying with the logos boundaries.
If you remain in the safety of the harbour waiting for a rhema word to move out will you ever go anywhere?
But do not rush off from those needed times in harbour for replenishing, renewal, repair cf Isaiah 40:31.
Need to recognise the season and respond to a Kairos (propitious) moment for decision or action - which could be a "it's time to cast off" rhema word.
Do not stay in the harbour out of fear. Jesus does use fear to lead us (cf. John 10:27; 1 Kings 19:11-13).

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See: https://biblehub.com/greek/4487.htm