I am indebted to Prof. Steven Abbott for pointing out that he has published an app that can be used to see the results of changing the drop diameter, contact angle and drop spacing.
As mentioned in the app there are papers that deal with the full theory of what happens and why but the model that can be used to find if the line of drops will say as drops, become a wavy line, will straighten into a smooth line or will form a straight line with bulges. I have made a start on downloading some of the referenced papers to look at the process in more detail. When I used to look at nucleation and coalescence it was important how large the nuclei were and how close with the biggest and closest being the first to coalesce. Which makes me wonder, how important is the accuracy of the drop spacing? If the drops on either side of a central drop have a different gap size will the central drop move towards the one with the smallest gap leaving a gap in the line? So it looks as if I still need to read more about the topic.
Prof. Steven Abbott then pointed me towards the following app:
This app does some of the sorts of calculations that were referred to in the article.
It is well worth everyone visiting the https://www.stevenabbott.co.uk Website as it is an excellent source of all sorts of information. There is plenty about adhesion of coatings that everyone should read. I feel slightly embarrassed that I had not done so, particularly as I suggest everyone else should do this, and had I visited the Website I would have found the app before I sent in the article to Converting Quarterly instead of having it pointed out to me after the article was published. Guilty as charged of "not doing all my homework."