First, definitely add both sources. You have clearly explained that one is a cenotaph.
Secondly, a suggestion would happen if the FindAGrave memorial dates or locations don't match your profile and you use FindAGrave as a source. Both FindAGrave memorials give the same death place. The suggestions don't check burial information.
However, your death place is incomplete. You should evaluate whether FindAGrave has a correct location for the time period. Sometimes, they use a current location which is not what we do at WikiTree, we use the location as it would have been known to the person in the profile. I know nothing about locations in Canada or I would fix it.
If the location you use is different than FindAGrave's location next week, you should evaluate your profile's location and also the location FindAGrave has. If you have the correct location, mark it as a false suggestion.
I added sameas=yes to the first FindAGrave template you have. This will ensure that only that source will be checked.