Generally, you remove anything that competes with the roots, water supply, & canopy shape of your "estate trees" (the big ones).

So I'd remove the smaller ones, *one by one*.

Remove the spindliest, step back & observe, maybe wait a day or a week to see how the view pleases you over time.

Pecan trees need a lot of canopy space & a lot of root zone & a lot of water:

Since you have an acre, put the flowering trees well away from the pecans somewhere where they won't interfere with your pecans' shape, root zone, or water supply-closer to the house where they can be seen from inside if possible.

Don't allow anyone to "limb up" the pecan trees.

So-called arborists often want to cut off lower limbs, & we're so accustomed to seeing trees pruned into the shape of broccoli that we don't think about the alternative.

Ancient pecan trees with enormous limbs sweeping close to the ground are graceful & impressive.

(& magnolias whose lower limbs haven't been hacked off are gorgeous & stately; they're the Southern version of a Christmas tree!)

These are just some minor "rules of thumb", but the main thing is to practice caution when cutting trees.

Once you remove a tree, you can't put it back, & your estate-sized pecan trees are treasures.

I would strongly suggest that you hire the services of an International Society of Arboriculture (ISA) arborist to examine your trees. He/she will be able to determine, in very short order, which of the pecan trees, if any, are worthy of saving. Pecans, if they are not regularly pruned and maintained, can become diseased and highly susceptible to breakage. A well-trained expert can identify such trees, usually from the ground.

By ALL means, if trees need to be taken down, you should hire someone. It's hazardous work.