Thank you for your question. First having limit break won't affect the ratings for melee physical attackers probably. They rarely use that in battle.

Second, Thancred has lower ATK, AGI, DEX than Stern's. However, in terms of HP, DEF, Thancred wins. It's a kind of tank units.

As a tank unit, Thancred's abilities like Heart of stone, Aurora, Camouflage, and Nubula works very fine with his role.

Third, Thancred's Shard can be obtained by trading medals for it. Meaning you can limit break it without spending Visiore.

Fourth, you have to see the unit's cost carefully. Some units have different costs event though their ratiy are same. High cost basically means that unit's potential. There is only 1 another 100 cost unit, Gilgamesh.

Okay understandable..thx for explaining :)
Thats whay i thought beacuse i was so atk oriented
So basically he's more versatile

This medals you said, is the goetia you got in the events quest? Is there any other way to get his shard after the events end?

Wait until the event occurs again, means you have to wait till next year

The wotv official has not mentioned when the event reruns. So the next year is possible.