30-51 no problems you say? And?
It's, or at least it should be, common knowledge by now that /drg is a fairly decent melee subjob, especially with some of the latent effect items. War/nin doesn't truly shine until at least 50 anyway, with DW2. When I was leveling my bard I ran parsers all the time, and 9 out of 10 a war/mnk, war/thf, and presumably even war/drg will out DD a war/nin pre-50, if they have more or less good equips, and their weapon is up to date. /nin doesn't bring alot to the table before 50, aside from some survivability and ability to adequately perform several roles at once, from decent tanking, pulling, and DDing, it's more of a catch all.
I'd rather be interest later on, against some 70+ war/nins and such. I'm pretty unbiased either way, as long as anybody performs well and does their job, I don't care.
The dangers I do see with this is, what is the war/drg wearing and eating, and what is he comparing himself/herself too, what is he fighting? Is there a SC, and if so what WS's is he using, or does he just spam as he gets 100tp. There are alot of factors that can really toss results one way or the other. You get a war/drg who outdamages a job/subjob combination during levels where said combination doesn't truly shine, but hey it looks good, and wham, suddenly that's the new thing.
War/nin is good for versatility, and personally I'd rather have a job that would do slightly less damage than one who tosses everything he's got in five seconds, does alot of damage, but then dies right away because he's not holding back anything because "omfg did you see what I did there".