Sako has proven himself a decent goalscorer when playing up front, backup to Benteke. He has become a massive, rigid player, with good technique and precise finishing shots.
He's definitely not the same Sako who used to play as a winger 5-6 years ago. He doesn't have the pace anymore. It would be a mistake to force him as a winger, as he clearly can't keep up.
So...imagine that Benteke stays. It is certain the club will still try to bring in another striker. IF that striker will be similar to Benteke, we'd find ourselves having to give space to both of them + Sako who will definitely deserve more playing time after what he's done+ Connor Wickham coming back from an injury.

This will surely force Sako out of the center forward area and into wide midfield, as he'll probably come in for Townsend or Loftus Cheek (a position in which I mentioned why he wouldn't flourish). On occasion, during second halves maybe, our attack could look like this: Benteke/Another big CF + Connor Wickham up front, with Zaha on the right and Sako on the left.

With 3 players like the 2 massive strikers and Sako on the left, this team is sure to concede a lot of goals. They don't do much defensively, they don't recover balls. If you think Connor Wickham will hardly play, you're only somewhat right. He will be given playing time. And if there will be 2 massive center forwards, it will only be possible for him to be brought into the game as a second striker, behind them. This will also mean no Zaha in the center, which has worked very well up until now.

I think this team doesn't need another big center forward now in January. If that happens and Benteke doesn't leave, I think a lot of goals will be unavoidable (for reasons described above).
What I think is that this team needs a short, fast, second striker. Or at least a player capable of operating behind the striker and doing both defensive and offensive work. And if such a player is not possible to find, then stick to Zaha, cause he's doing a great job.

Course, all this talk would be for nothing if Benteke left. Then surely another player would be needed to step into his shoes. With Sako as a center forward backup, which he has proved he can be successfully.
No matter my feelings over Benteke (I'd sell him in a jiffy!), but objectively speaking, not taking into consideration how I feel for him, if he doesn;t move, I don't think bringing another center forward in can help the team

I respect your opinion, but that's not going to happen after he has scored the many goals he has scored coming on as a sub.
He'll be moved to the side though if another center forward comes in. And with his current weight and mobility......he'll surely be no Townsend or Zaha

I want to stop you right there...

Well, he's gaining cult status and he surely will not be sold this winter.
He has hardly played and scored 2 times in the league and 2 times in the Cup, from center forward positions.
I don't rate him much either, but he makes a decent sub. He still has 3 goals more than Benteke, in less than half the playing time

Let's have it right, Sako is a championship level player. That seemed to be agreed universally until he scored a good goal against Leicester, and now he's all of a sudden a cult hero? Not so sure about that.

He's done decent off of the bench in one game, so this terrific goal record you speak of is strange. Statistical stuff that doesn't take into account the fact he hardly ever even plays for us, and the actual amount of goals he's got is hardly any.

I'm not so sure Roy fancies him as much as you'd believe, considering he started with Wilf and Townsend on the weekend and personally I think that's a lot more of a scary frontline for defenders to have to deal with despite the fact that neither are traditional strikers. Heck, Sako might even score a couple more but if we lose Benteke again and he has to start games, he'll get found out pretty quickly. His only assett is a bullet of a left foot, which can be useful at times, but his footballing intelligence, and awareness of team mates is so poor. Let's not let an all be it very good goal cloud that.

With the money involved in the Premier league, you'll find most stable PL clubs will have premier league quality even in reserve. This has been for a while our most pressing issue (squad depth) and one we desperately have to start addressing properly. We need a new striker, possibly even 2.

For what it's worth, I agree with the type of striker we need. I think Benteke is a quality player, and can be utilised excellently in away matches. But at home, in the high intensity pressing game Roy seems to like - I think we need a bit more energy and unpredictability.

We're the Arthur over ere!

Danny Ings wasn't very fast before breaking his leg and surely isn't any faster now