Yes John, that makes perfect sense. Just looking at Dublin Apt's (sheltered east coast region) averages here, and they seem roughly similar to yours (73mm) for August.
I would imagine that rainfall wise, the east of Scotland would compare favorably with that of the east of England? which I know from experience is a very dry region of the UK.
I did visit Dublin back in the autumn of 2010 in what to date, is the one and only trip to Ireland which I have made (since that incorporates the whole island which is geographically known as Ireland, you will have seen by process of elimination that I've never actually been to Northern Ireland) and what at time was also the first location which I had ever visited outside of the UK.
For most of the time when I was there, the weather was generally OK for most of the time, although I remember very well, that wind which blew through the valley every time I crossed the River Liffey which passes right through Dublin's city centre. There was the odd dampish day when I was there, but I can also remember one really wet day when I was there, when the rain went right through me and I got absolutely soaked.
However, the fact that Dublin (along with Belfast in Northern Ireland) lie on Ireland's coast means that I would therefore expect it to be drier there on average than most other parts of Ireland and to a certain extent, I probably benefited from from that quite a lot when I was there. As far as Edinburgh is concerned though, it is true that our rainfall totals are comparable with many part of of the east of England and it turns out in fact, the we actually get less rain here on average than places like New York over in America.
The north of Edinburgh, usually always missing out on snow events which occur not just within the rest of Scotland or the UK, but also within the rest of Edinburgh.