all CR agencies are stating that my low limit ($420) orchard bank CC @ 14.9% APR is also hurting my overall scores.
This statement is probably advice associated with a FAKO score rather than a FICO score. You'll never see it on FICO reports, but I see it on my FAKO CCT reports for all 3 CRA's everyday.
CCT (and other sources) provide FAKO scores and FAKO comments such as the one you're referring to about low credit limits on your cards, which it's best to totally ignore. Following FAKO advice can and will actually damage your FICO scores.
FICO will never ding you for low credit limits on your cards. And closing a bank card (which your Orchard is) will definitely hurt your FICO score because FICO likes to see a bank card. - it appears that Orchard is your only candidate in this category (for the time being). I'm not familiar with USAA and don't know if it codes as a bank or a credit union. I would definitely keep your Orchard open until you get an additional bank/national cc revolving account or card.
DH had a lovely 804 score with only one cc (an Orchard with a CL of $500)!
Keep to the FICO scores and advice - and if you do pull reports from other sources (as I do), ignore all FAKO scores AND advice.