They have bad luck in minor things, but awesome luck in major things.Ironically, many ppl have said (myself included) that the Romans seem to suffer from hideously bad luck at several points in this TL.
It's a funny dynamic, because I agree that tactically, they've gotten a lot of bad luck for a long time. And yet they haven't suffered a serious strategic reversal since the time of troubles, a hundred years ago. And there, they got rescued from what should have been a much harsher beating, and transformed into a much stronger, pound for pound, state. So really, ITTL has just been success after success at a broad level since the pod, and recently they've had a string of bad luck on the smaller scale that muddies the waters on how lucky they actually are.
Luck doesn't bother me, one could make the case plenty of major empires OTL were incredibly lucky. Thats not a criticism in any way, just the TL as I've seen it. But I do think if you just look at the tactical mishaps you miss the incredible strategic strides Rome makes.