Well done. So often people just have the surnames and given names and think people are automatically related because of that.
In the event anyone is interested in searching Castlepollard Roman Catholic Records (I assume they were all Roman Catholic and not Church of Ireland (Anglican) or some other religious denomination), here's the link to the Roman Catholic parish records including the dates covered in the microfilms and where they can be searched:http://www.ireland.com/ancestor/fuses/rcparishmaps/index.cfm...
You'll see from the Roman Catholic parish maps for County Westmeath that Castlepollard parish is on the border with Counties Meath, Cavan and Longford. Depending on where the family members were in the parish when events occurred, there might also be records in adjoining parishes in the other counties if they were located closer to the Westmeath border of those counties. Of course, there was no requirement for them to stay within their own official parish boundaries. See:http://www.ireland.com/ancestor/browse/counties/rcmaps/westm...
There were many, many Boylans for example all over County Cavan.