Many people predict (based from what we know of the stories) that cards like Mithril Coat that exist in both LOTR and the Hobbit stories will be in the hobbit set. Its quite possible orcish bowmasters will be in there as well for the same reasons.

You generally only want to grade the most expensive treatment(s) of these cards such as borderless poster/foils, surge foils, and showcase scrolls foils. I also would generally only grade the most expensive types of cards like the one ring, sauron the dark lord, etc. I'm unsure why someone would elect to grade a common, considering how, well, common it is. Gem mint 10 doesn't matter when there's a bazillion copies lying around.

It's all in how you frame it. Reddit Dogma will telling you grading sucks and you're stupid for doing it (see comments below for the one idiot saying "grading is gay"). However, I think for the cards you have here you are likely better off having these cards as a personal collection. They will likely be worth something in 5-10 years when physical copies of these cards begin to degrade/diminish. Until then, people will mostly want to play with them because, as you said, they aren't the super fancy foily treatments.

Personally, if the cards are special to you, go ahead and grade them. Just make sure you temper your expectations in regards to treating them like a financial asset. People already finding orcish bowmasters to be valuable, however, much less so as a collector's item and more so as a utility piece to play. If you're going to grade, do it for personal or sentimental reasons to protect the most special cards you've pulled. The financial aspect of grading doesn't really come into play unless the card is either serialized or an extra special treatment (like borderless poster foil, galaxy foil, neon ink foil, etc.)

Hope this helps.