I had a hymenophysa the same way. These various botias can hide their true coloration quite well when in a stressful location. Stripes totally disappear, coloration changes to match that of the skunks...now that I viewed those links I am thinking my hymenophysa could have been a lecontei (never seen the striped pics before as I thought it was a colored fin loach).
The tiger loach I had was aggressive with all fish. Even while only 1.5" long it would harass my angelfish (2.5" body at the time so roughly 6" total size) if the angel would try to get any "sinking pellets" near its territory. Once these guys are comfortable their true colors come out strongly. The meaner the loach the shyer the loach from what I have seen so far. The only time my tiger wasn't shy was when it was trying to beat up the other loaches. Yet even the tiger would not try to attack me....(it was around 2.5" when it met its untimely demise).
Are these the ones you originally thought were skunk loaches? I have never seen any of my loaches eat anything green. All loaches I have had, even when moved from one tank to the next, will check every single plant, hiding place, etc, to find snails. At first I thought my yo-yo loach was thinking about eating some plants but I watched the way it dug through the java moss and deftly climbed through my hornwort whereupon I realized it was looking for snails and uninterested in my plants for any other reason.
If everything stays on the opposite side of the tank it will probably get worse in time (thus why I moved my sun loach into my 10Gallon tank and found a new
QT and the sun loach is a pansy compared to the tiger loach). The tiger I had (which may have been lecontei) was very aggressive and near the end actually had the skunks hiding behind my filter and heater (resting on the suction cups of the heater). I say it is bad news unless you have a very aggressive tank for it to go into if it is the same fish I had(I thought I would keep mine around to keep the skunks busy since I wanted 3 skunks total to keep them occupied with fighting amongst themselves but nobody could handle it though it did mostly just attack other loaches).