>>96416280
Yeah those four models are one unit, since the company heroes sprue contains a captain and the rules dictate you must attach a captain or chapter master to it, it's essentially a captain + 4 company heroes models so a whole unit. As to whether you can attach anything with Captain or Chapter Master keyword, I don't think so. BT Marshall has Captain keyword so it fulfills that requirement, but Marshall's datasheet doesn't say that it can lead Company Heroes. Pedro Kantor of Crimson Fists says it can attach to Company Heroes for example.
>>96416269
Thanks. I suppose I can trap the bikes with the infiltrating Genestealers and on the 2nd turn I can try to take them down with the Primus + Neophyte deathball. It's going to be at 1000pts, and it's also gonna be my first time fielding a ridgerunner. Let's see how it goes.