Hello,
Its good to post short blog of 100–150 words because this type of short blogs has lot of engagement on social media and mobile users. Now days SEO has been changed so it do not matter how long you write. If you are fulfilling the basic requirement for SEO and your content is meaningful then you can come up in search engine ranking easily.
Stuffing of keyword in content is old school technique by SEO so if you are using keywords in phrase then it will be too good for you.
Thanks