It would be really nice if you could request pageview statistics for a page and all its redirects. For example, if you requested:
https://wikimedia.org/api/rest_v1/metrics/pageviews/per-article/en.wikipedia/all-access-with-redirects/user/Cat/daily/2016031200/2016033100
... it would return the aggregated pageviews for "Cat", "Felis domesticus", "Housecat", etc.

Note that the redirects API is limited to returning 500 redirects at a time, but that should be more than sufficient.