That's all I ever used. I use a group 24 Costco deep cycle battery on my 59 hp,Volvo Penta diesel - have been for years. My house bank is 5x Group 24's. When my house bank gets weak I move one of the house batteries to the starter battery position and get new ones for the house bank. If my starter ever falters (it hasn't so far in 9+ years) I'd just use the battery switch's combine-position to add in the house bank. So I view the starter battery as part of a redundant system.

IMHO This whole CCA issue is really only an issue in cold climate, cold engine starts. You need lots of CCA in Minnesota in January, but not so much when the weather is above freezing.

As for the issue about damage to a starter, I really don't see how that's possible unless someone just holds their finger down for a looooong time on a starter switch that doesn't have enough juice to turn-over the engine. But in practice, reasoning says if it's not turning the motor over you need to address the problem; by looking for corroded contacts and/or use the combined house bank to get more juice.