i would subtract sims and add mahle, but otherwise i completely agree -- both in terms with the players you mention and that it's the weakness of the roster right now. with as aggressive as the reds were this offseason, i am surprised they only signed one reliever, and it was relatively on the cheap with strop ($1.8M guaranteed with the potential to earn an extra $1.7M if he hits all of his bonuses).
i realize a lot of people think that if mahle doesn't make the 5-man rotation then he should just go to louisville and start, but i want the best pitchers coming north. there is no doubt in my mind that tyler mahle is better than lucas sims (although i do like sims) and can be used as a long reliever unless/until a starting spot opens up for the reds. i also get the strong feeling from david bell's comments that he really likes mahle. i'm pretty sure i'm in the vast minority here, but i feel like mahle is a near-lock to make the opening day roster because he will be viewed as one of the best 8 relievers for sure if he doesn't make the rotation. and since the only way he's making the rotation is if someone gets hurt, that means he will be in the pen to start the season imo.