Gerald,
As you suggest, you wish the second level to be sorted differently to the first, we must also ask what about the third and forth levels?
I do not recall the standard toc macros being designed to handle this. I have posted a number of occasions on recursive macros which a toc macro is. I have also give examples of level type macros that treat each level differently (a few levels only). For example you could call a macro that sorts in one order and for each of the items below call another that sorts in another order, but then perhaps always, sort levels further below that, in one particular way.
I your example you only need to have one list inside another list, and each can have a different sort order. However unlike the TOC macro it will not drill down into deeper and deeper levels.
One though I had it to make an advanced macro that looks to see if there is a sort filter (field) on each tiddler, and sort the children by that if it exists, otherwise use the default sort. In which case you would need to set this alternative sort order on all tiddlers at the level you want the different sort.
However you could have your top and second level list's nested, then for the children use the TOC macro to go the rest of the way down.
I can give more details to morrow, but see if this helps you understand the issues.
Regards
Tones