Dave take a look at Wisc Fish (see archives under id sources). They show lots of pics of X rakers and provide that they are intermediate of the two parental species. They have no RES morphology info and that is in short supply elsewhere. Get a copy of Peterson's Field Guide to Freshwater Fish it has very good morphology info.

I think 4 is a RES by looks and morph. I learned a long time ago that pics on here can look very different depending on the computer and screen. On my screen no 4's pectoral fin looks almost exactly like no 1's shape, size and length on Bill's I assume it looks different. I note that the 2 BG ear flaps look much more different than the 2 RES do. On my screen the scale pattern goes almost up to the eye on both RES and their head shape is similar as are the 2 BGs but they are different from the RES. Faint black spot on dorsal of BG not on fish 1 or 4 (this is noted as a major morph difference between BG and RES). The difference in size of the 2 RES could be from a # of factors like actual age ( in the south RES often spawn more than once and/or the period is spread out), aggressiveness or male/female , or parents genes. Because the spawn can be spread out the early stage food supply can be very different for 2 birth dates 60 days apart thus there growth rate/size. RES have short stubby gill rakers while BG are long and thin and Xs are medium length and width. As both Bill and I stated this type of id can be hard/problematical sometimes especially in small fish. All of this and a dollar will get you a cup of coffee. \:\)