I would love to have someone tell me how to get rid of that grass, I have tons.

It’s hard for me to tell from these pics, but it looks like Johnson Grass. I’m not positive, though.

If it is, it’s pretty easy to pull-up, but wear good gloves. The blades have sharp edges. I know someone who had to get stitches from grabbing them the wrong way.

It really barely (or not at all) matters in this context what its name is. It's a weed grass and should not be allowed to get so large before being removed. It especially should not be allowed to produce any seed or you'll be looking at removing much, much more of it. I would get it out and subscribe to Preen at regular intervals (per directions) for ahile.

One solution to perennials splaying outward it to have the bed be thicker with them so adjacent ones are splaying into the area of those that splayed outwards.

I get that in my flower beds. They have runners, so when you pull them, you have to make sure you get the runners underneath or they will just come right back. I've had to dig up the plants to get all the runners out of them.

Put on some thick rubber gloves on, then put some cotton gloves soaked in weed killer over top of the rubber gloves and stroke the weed grass, being careful not to touch the Salvia. I've never actually done this though.

The double-glove method would be fraught with peril, as well as waste of herbicide.

I have done the double-glove method in tricky situations and it does work.... if you're super careful.

As to the splaying: use a plant ring that you put around the plant before it gets very big. Unfortunately it's probably too late to do much about it at this point this year. I have some rings that are quite old that have several increasingly larger rings inside the biggest which has the rods that go into the ground. This is especially good for plants like this Salvia. The whole is about 24" wide with legs that are about 2-3 feet long.

You can't kill that weed with weed killer, it has runners, pulling it is the only way to get rid of it.

The weeds in the center of the plants are contributing to the splaying. You need to get them out before they choke your plant.

Think the whole clump needs digging out, dividing into 3/4 clumps and removing the grass rhizome at the same time. Unlike bindweed, the roots have enough tensile strength to be cleanly pulled out in skeins. Water well until all clumps are established (this is key) I have often moved plants in full bloom and vigour. The salvia will grow away immediately.

Unfortunately, you're just going to have to get down there and pull it out, unless you want to tear out everything else and attack it from that angle.