Cut/ mow it.
Rent a towable self powered mower and have at it.
I watched briefly a guy cutting old field the other day. Just knocking it down.
On another sight a guy had cut and was using a blower to clear the mowed area. Rich soil so he wasn't worried about thatch probably. And an established clean field.
IF you own the property and will work it in the future you have all winter to make short and long term plans.
Regarding how to intersperse plots within a field broken up by fallow areas , what is around it matters.
You have some shrubs in the pictures distance. Are deer using that "line" to cross the field?
If they are the sides of the field and points beyond likely factor.
Given encouragement , cover along that line can be increased. IF you want deer to use it.
Deer like browse areas where they are a jump or two away from cover (when not in a destination field and using distance as security.)
By leaving a generous buffer of fallow area along your field edges you're creating more than just field edges. Now there's a transition zone creating more edge. And security if open field is not the moments desire.
Lots you can do. But how deer use the area now is easier to enhance , than creating a reason for how they use it only. Both can be done. Yet that's an example of short and long term.
Trails at the edge of your buffer on field edges create more edge.
Micro plots within the fallow field can be just out of sight from those edge trails.
If you're going to shoot deer in/on a plot put it where you can get in and out without getting caught. And be able to hunt in varied winds. But give deer a place to browse unhunted too. Such areas can be located to make it difficult to access as a predator without getting caught.
That "line" along shrubs after being developed for more cover can have a trail kept cut along it. On which side?
Should that trail be connected to others?
Straight trails , or meandering trails with curves?
It depends on what you want for your visibility , or deer visibility. There can be a balance.
If you have great cover beyond the picture you can focus on more plots scattered about per a design.
If you lack cover , use your field to develop cover. With small plots and trails kept maintained.
Trails can offer what a plot offers. That affects where you would have small plots. As it does your volume of browse.
Being four acres , a half acre of browse would be a good start. And not a horrid balance vs cover.
By the time you add trails (might as well if you are going to provide browse / plots that is screened inside the four acres) there's going to be small area /volume remaining to reach half an acre.
Expand each year if desired by removing fallow ground that doesn't suit your cover goal/design.