Cue!

Both touches on the job of the voice actor. Cue! is more "positive" in the sense that while some reality is depicted, not all of them is shown (at least thus far). Sore ga Seiyuu! is more realistic and is more "faithful" to the traditional job of a voice actor (e.g., less stage performances and more behind the scenes). Regardless, both talks about voice acting and features rookie actors. 

Both shows are giving insight about anime production, but from different perspectives. 

Looking for an idol anime but with less singing? Then these anime will definitely catch your attention. Cheer Fruits follows a Tokusatsu performance group, while Cue! follows a voice acting company. But both follow traditional idol tropes, reference other series, and poke fun at their respective industries. Cheer Fruits has a much smaller cast and clear storyline, while Cue! has a massive cast with a strong slice of life, episodic format. 

- Group of girls just starting out in their respective industries (Seiyuu and Idol) - Wholesome Cute Girls Doing Cute Things content without ecchi - Seiyuu for main group of girls are brand new to the industry or nearly brand new - Neither group's goal is to make it to the top of the industry; they just want to find success and be happy 

Both are Pony Canyon's multimedia franchises, same studio pair, both doesn't focus much on the reality of being an idol/seiyuu (afaik) 

As I watch Cue, I get the same feeling for Haruna Mitsuishi as Maya Katajima. Both are highly versatile actresses who turned roles that were originally intended to be background extras into featured character appearances. Both deeply move someone who has a treasured work she wants to see performed. 

Both animes are about the voice actor job. There are a group of girls wanting to be voice actresses and getting slowly different roles. However, the difference is that in Girlish Number the MC started being a really bad voice actress, and in Cue, all of them are decent... There are more comedy y GN than in Cue, and the plot is about one group and not several like in Cue 

Large roster of characters, each with their own characteristics, motivations, trials and tribulations en route to becoming a top idol/seiyuu.