Learn English – “Stretched too thin”: Would the meaning of the phrase change without “too”

My colleague, a native-English speaker, in his message apologized for not replying to my emails right away.

I know that he is an awfully busy person and besides his professional activity and family, he has his old mother to look after, his children born during his first marriage to support, and so on and so forth.

What I want is to ask him, both politely and idiomatically, not to apologize and, as soon as I understand his situation, I’d like to add a phrase that would show my understanding.

I was thinking of the phrase:

I know you're stretched too thin on several fronts.

But “be stretched too thin” means that a person who tries to do many things at the same time, can’t give enough time or attention to any of them.

With my friend, it’s totally different:

He does many things at the same time, giving enough attention to them all. The matter is that he has to temporally sacrifice one or two of his responsibilities for carrying out the others, thence he may be a little late with carrying out those others.

In this regard, the phrase “stretched too thin”
to me, seems somewhat not matching the real situation perfectly.

I thought, what if I use the phrase “you are stretched thin on several fronts” (without "too")? Would this hit the bull's eye?

Could you kindly suggest a couple of phrases of the same meaning?