粗俗=粗鄙 vulgar,coarse
粗疏--粗疏荒率 inattentive, careless
In my attempt to explain: 粗俗粗鄙 implies that things have gotten done, or words have been spoken, 粗疏 or 粗疏荒率 may imply things did not done at all.
Sometimes, time is important than quality, so rather 粗俗,粗鄙 than 粗疏 or 粗疏荒率. Expedient measure works, better than nothing. My past experience tells me that I worked too hard on a piece, and lost competition by that. My new work improved by using simplified background