Well here's what I would say:
1. IF we add a RB, it's not going to be a world-beater. It's mostly just shuffling deck chairs on the Titanic at this point. Like even if you managed to get Marlon Mack, who would be on the very, very, very high end of people we'd be going after, I'm not sure he's that much of a difference maker. Better than the guys we have, but not a massive upgrade. I don't see RBs available, or who will be made available, that are going to turn this rushing attack into a 2020 or 2019 version. It's just not happening.
2. If there's a personnel upgrade, my money would be at LB or somewhere on the defense, likely in the secondary. Not even a 1-6 team is going to trade a solid Olineman, and we certainly can't afford anybody of note anyway.
Bye week should be about a) getting some injured players back (Wolfe, Boyle, Watkins) and b) spending every second of every day learning how to fucking tackle people.
If this defense could actually execute on tackling consistently, they'd be at least average. And an average defense, especially in this division and conference, is going to win A LOT of football games.
Offensively, we're pretty much stuck with what we got. We've got some injured players who will come back, and the positions we could use upgrades are probably unrealistic to be upgraded. The defense is where I see some talent issues that will, of course, be addressed in the offseason, but I'm not seeing many options now.
For all the complaining we do about the Oline and the running game and the offense... this defense has basically played two good football games in 7 weeks. They played probably a good half against KC, I didn't even really think they were great against Detroit, even though they held them in check on the scoreboard pretty well, and they played great against the Chargers. Defense was bad against the Raiders, bad against the Colts, bad against the Bengals. And all three of those teams are playoff contenders at the moment.