Here's a rough and baggy peasant's shirt. It will probably not work for you. I shaped and wrapped it specifically to fit on Lubga, a busty goblin, and it doesn't even do that well! But it is fun to watch it slide off her, and it may be useful for some other peasant, beggar, or otherwise financially disadvantaged shortstack.
Play with the alpha value and diffuse bump level to make it look more or less threadbare!
A the risk of unrealistic expectations, I'm including a preset with physics settings to help it fit on a base model. Still, please don't expect it to work well.
This is the Tunic portion of a very nice medieval male peasant outfit by Red_Ilya, which I hope to port over in full (and without ruining its shape to fit an impossible
Source: "Medieval Peasant Outfit Free" (https://skfb.ly/pHuFS) by Red_Ilya is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).