Hard to tell the sex right now i cant wait to see pics of them settled in.That's a hard call to make as far as testing them. I would try the faders ASAP if space is an issue and you didn't get them just to be nice display pieces for they are the least likely to be fertile and you won't have any trouble moving them along. For 100% accuracy test them to known fertile mates because I have had 2 infertile egg laying females so far myself (tested with known fertile males multiple times). Any idea on lineage because to me they look to have pretty consistent traits with one another (for rts) and good Texas conformation so your chances are better than average (for rts haha). They are either very very nice f1s, or a recent crossback fader rt female to pure (shortbody) carpintis, or best case scenario line bred from fader x fader and we know that's not too likely. I would almost suggest picking up a nice female kkp to try your males with because if fertile their fry can be used to start another line so you aren't at a dead end with them too early. You could do a male x female from these then cross out the fry from these to the rt x kkp fry to keep slamming them full of Texas and fade genes. It's tough to plan a line with these things because of the infertility issue. If you have the space I think your best bet would be to kind of let them pair amongst themselves first because if they take you are going to want those fry lol but if they don't hatch you really didn't learn anything about either parents fertility.
So from me you got no real answer haha but maybe an idea on how to start. First things first gotta sex them. So far and I'm just guessing here but it looks like most of them are males.
