How would you pan these strings?

What's the genre? How independent are the parts? Need more info, but generally speaking, if it's contemporary/pop and the more dense the setting, then on the wider side. If more classical/chamber sounding and more intimate, then I'd keep them together (narrower) and in sections. At least that's how I would approach it ..then adjust the spread to taste.

Are they all on separate tracks?  If it's pad, go a little wide, if it's a distinct part put them all in an area together. Of course it depends on what else is in the mix. If there are two guitars, hard L&R, the strings can stay inside that arc, around the settings you posted.

I personally like to pan them as if I was looking at a string section of an orchestra. Each person a little to the side of the next in small panning increments.

Yes, Blackdawg, you're right, the reverb choice does help widen the strings in a way that maintains focus.

I dont know....ive never NOT had cellos. I usually go violin and cello for a sparse thing. Them move to two violins and a cello before I bring in a viola section.

It has a lot to do with whwhere theres space....what the symmetry is without them....but, mostly i would think 9 oclock and 1oclock. Maybe pan (their sends into) the reverb a little to the right to provide some balance.

Or do the same except do

Violin - violin - violin (lead) - viola - viola. The way you might pan a doubled rhythm guitar with a lead. The stereo contrast between violin and viola with a violin center may be cool vs the balanced stereo image blackdawg gives above.

In Pro Tools readout 60L 30L 30R 60L
Viola 1, Violin 1, Viola 2, Violin2.  

I should have added that part, sorry.  

I suppose my first question would be to ask: Are they are the same tracks done multiple times to "thicken", or are they multiple parts?

Second question would be to ask if they're part of the main melody, or supplementary to other instruments..

Those answers would determine my response, which would be that if they are multiples for thickening each instrument, I'd leave them panned close to one another and move the group slightly to one side, and the other group done slightly to the other side. Maybe Violas Left at 20%, 30%, 40% and violins Right at 20%, 30%, 40%..

If each track is multiple parts, maybe leave them layered on top of each other and just pan the group slightly to the sides of center and add a little ambience.

Or if they're just supplementary, pan them all LCR as a bed for the rest of the instruments.

I had to do that once.... Violins and Violas...... I ended up stacking them and putting them in a room, kind of sounded like a vocal harmony.