KEP 1645: clarify the chosen conflict resolution algorithm

This PR attempt to explain the reasons why the resolution algorithm was
chosen by considering other conflict resolution algorithm in the
alternatives sections and explaining why those were not selected.

Signed-off-by: Arthur Outhenin-Chalandre <[email protected]>

Author: MrFreezeex

keps/sig-multicluster/1645-multi-cluster-services-api/README.md

@@ -118,6 +118,7 @@ tags, and then generate with `hack/update-toc.sh`.
   - [<code>ObjectReference</code> in <code>ServiceExport.Spec</code> to directly map to a Service](#objectreference-in-serviceexportspec-to-directly-map-to-a-service)
   - [Export services via label selector](#export-services-via-label-selector)
   - [Export via annotation](#export-via-annotation)
+  - [Other conflict resolution algorithms](#other-conflict-resolution-algorithms)
 - [Infrastructure Needed](#infrastructure-needed)
 <!-- /toc -->
 
@@ -1240,6 +1241,22 @@ achieve the same result. As the use of a multi-cluster service implementation
 would be an optional addon, it doesn't warrant a change to such a fundamental
 resource.
 
+### Other conflict resolution algorithms
+
+When a service has a ServiceExport and a ServiceImport, we could have taken the
+approach of favoring a "local truth" by giving a higher precedence to the locally
+exported Service in the conflict resolution algorithm. This alternative
+approach was not adopted, as in this KEP we favored global consistency across
+the ClusterSet.
+
+The conflict resolutions algorithm could also have been based on majority
+instead of ServiceExport oldness. However, with this approach, we would have
+to consider a tie breaking factor that could have also been based on age. This
+would complicate the implementation of MCS-API and, most importantly, might be
+more confusing for users. Having just one simple deciding factor based on
+ServiceExport oldness makes resolving conflicts straightforward, and this
+alternative conflict resolution algorithm could hinder this ease of use.
+
 ## Infrastructure Needed
 <!--
 Use this section if you need things from the project/SIG.  Examples include a