One large monitor is not equivalent to multiple monitors. You need to look at the resolutions for each monitor, and the amount of information you want to view, and to what level of details.
Most large monitors are only 1920x1080. May be the same as small monitors capable of 1920x1080. This only means you can see the same image, only bigger in size. Unless you purchase the higher resolution monitors, like 2560x1080, or 2560x1600. But those can get expensive. (e.g. $650 for one monitor, instead of $110.)