Do you mean a ratio of image scale (Arcseconds per pixel) between the imaging and guiding cameras? If so I would not worry too much. I use an ASI2600 on both a 10"F4 newtonian (About 1100mm focal length with the Paracorr in place, similar to the Esprit) and my Stellarvue SVX80T (480mm focal length) using a 290MM mini on both and both guide just fine. I tried the one on the newt at 2x2 binning but it did not make any measurable difference to 1x1.
I assume you mean this OAG?
https://astronomy-imaging-camera.com/product/zwo-oag
Within reason any decent OAG will be fine so long as the clear aperture is big enough to avoid vignetting, there are adapters available to fit it in the image train and you have enough backfocus to play with.