You really do need to try and promote. Not just because you'll make more money, but also because you will have actual competition and won't get bored.
So you have a team full of scrubs right now, do you have a training plan? If you have a halfway decent one, you shouldn't be all scrubs by the end of the season. If you need to, go out and spend 100k-200k on trainees, and put together a solid training plan. 5-6 guys, train either inside or outside for the rest of the season, and you'll be just fine in D. IV.
I was competitive in D.IV after 2/3 of a season in D.V, going 19-3 my first year up. You have a full season to get ready, I'm sure you can do it.