I have to disagree there. There is definitely a point of diminishing returns and counterproductivity if you have too many people working on something, but DC isn't employing anywhere nearly that many people. The work that needs to be done requires a certain amount of man-hours. More workers would make the work go faster.
Not necessary, there is something called "productivity index", it helps to calc how many workers in theory you can have to do a job. But there are aspects to consider it's value which aggregates troubles, first and most obviously for this game is the lack of artists, because DC value consistency in the art as far as i know there isn't others, now he have more developers, before he have no one iirc, this tech update will not only update how the game looks but it will free the game of some bugs and things that DC did and was giving troubles in coding this game, for that, you need an equip of ppl who need to be in accordance of the way variables, functions, etc will be declare, named, etc, and all that is what is happening in this tech update. But as i said in the beginning, having more workers not necessary will help in making fast things, there must be supervision of the coding, not only for bugs but if the programmer is doing the planning according what was established because in the future it's needed a variable and wasn't called properly by an spelling mistake for example, this can make future updates make corrections for past works and worst, can make saves incompatible. So, having more people would aggregate more complexity too, and that means a necessary spend of work/time to do.