Couldn't Suicune have picked Seph anyway? I mean I'll probably edit Suicune so that it fits the "picked from birth idea", but would Seph, who doesn't know about the whole fact that suicune picked him, really need to like suicune to be a good partner? My thought process was that Seph accepts it first out of need, but it grows into respect. It gives room for some growth instead of "OMG Its Suicune the greatest pokemon of all time!!!" *swoons*. I did explain Seph as someone who had a lot of hope, resolve, and values (even though those are now locked away), Suicune may have been caring a bit more about those then Seph's personal preference.
If there really is no middle ground I can edit it, but I do think it takes away from the possibilities.
That's okay. Now that you've explained it, and that it's all clear, you're accepted. Welcome aboard!