Question

although Jo is tall he is not strong (begin with tall as...)

Answer 1

Tall as Jo is, he is not strong.

or

Tall as he is, but Jo is not strong.

This structure (adjective + as + subject) is used to say that in spite of something being true, what follows is also true.

Examples:

Try as hard as me might, he could not life the heavy box.

Study as much as he would, he could not pass the test.