It's not a requirement to finish any of the savages, also I don't believe it's required to do the extreme's either for the main Story. I see a decent amount of parties up for mount farm in PF that are usually pug groups. People still do Alphascape V.4 for the mount. I can see why you would want this due to not having the time to farm them but there has to be some sort of time gate for mounts to keep people playing and trying to get it. Every MMO has a grind in it, some of them are worse than this. If you think about it, 50 totems. You can easily run like 5 times within an hour in a good group. 10 days would get you the mount if you only had 1 hour a day to spend.