Maybe. Depends on whether they're being cast with new actors or existing actors. If existing actors, then it's just him rewarding his friends/lackeys. Remember that these large series with reoccurring characters means relatively steady work for the VAs cast in those roles.
On a related note, people should probably be questioning "What series other than Dragon Ball?" when talking about Sabat. Yeah that's a big one, and one he's had a long standing personal interest in. However he's said to have large amount of casting control at Funimation in general, not just for Dragon Ball. So how much control does he have over the casting for Fairy Tail for example? A series with 300+ episodes and a
massive cast list that has definitely seen the addition of a number of newer actors and actresses over the years. Or One Piece which has over 900 episodes, and an
even more massive cast list. If he controlled casting for them, you can go through their cast lists, find actresses in their 20s, 30s, or even early 40s, who started at Funimation (or even voice acting in general) in the last 5-10 years, and ask yourself "Did they have to go through Sabat to get the part?"