The first phrase in your question reads as if you are connecting one root position triad to another, then another.
Since the question sounds like one from a beginning level theory student, I assume you meant the root position triad moving to another harmony, not usually another in root position.
If you are talking about those 16 or 32 measure long exercises, and staying within the limits of the chorale as usually presented in first year harmony, whatever you write will probably not travel enough if you follow that set of limits where there are 'no large leaps' in any of the voicings to end up in much of any type of wide open spacing, especially within the shorter 16 measure sort of problem. But, even within those first year lessons limits of moving close to step-wise you could adhere to that and within sixteen bars still smoothly arrive at one or more widely spaced harmonies, which would of course be 'open.'
If I recall, there are some loose guides as to generally how large the intervals are between one part to another to call them either open or closed. You should use that guide on a case-by-case basis to determine whether those chords are one or the other.
I think looking for some general rule of probability is, at this juncture in your study, anyway, looking for an easy shortcut where you can then think less! Sorry, you have to think all the way through.
The
reason for that thinking it all the way through now is that by next term you will probably be able to look at a chorale and quickly tick off the open and closed chord voicings in a manner which will feel nearly innate, i.e. the thinking and work done now sinks in to a point where only a bit later
you just know, and don't have to think about it. Besides, the second term and subsequent levels have something else new to you which you will again have to initially think all the way through. Best then to have those previous fundamentals down pat
Best regards.