Centaurs are a pain in the butt to solo. It is not impossible, just time consuming. This applies to all centaurs, not just shelties.
-THEY ARE FAST: Faster than my druid with SOW. Snaring is absolutely a requirement. If the fight goes against you, make sure you have enough mana to get a snare off. You are dead if you don't.
-THEY ALL ARE ARCHERS: This is the number 1 reason centaurs are so tough to solo. IF you get to far out of melee range from them they will shoot arrows at you. The arrows will stun you and interrupt your casting. This greatly lengthens the time to kill them. I almost always have to recast snare a second time, and take a few 40 - 50+ point hits while trying to get a snare off. The average damage from an arrow is around 10pts per hit.
-THEY HIT HARD: When in melee range they hit hard for there level. If you have ever tried to solo a grifFAWN in NK or EK, they hit that hard and fast. Don't even think of meleeing one unless it starts to turn and run.
-THEY AGGRO: on you if you are kiting one and come to close to another one. Unless your close to the NK bridge or Lake Rathtear zone lines, you are dead if this happens.
I usually go after Aviaks as they give similar loot and experience, and don't take as much time and mana to kite to death.
Davis Longstreet Human Druid of Karana (20 seasons)
I agree also except for one thing. I was near the bridge today, fighting one of these guys, and one of the named ones snuck up behind me. I was sowed and thought I'd fine but no. Both hit with arrows, stunned, then killed, right at the bridge. I wont be messing with them again for awhile.
Three centuar shelties managed to run down and kill my SoW'd 16th level shaman. Their arrows do stun damage, upwards of 30dmg, and they can hit from a very far distance. Interesting note is that Invis to Animals works on these creatures.