Ako pridať ďalšie zoradiť ak reťazec začína deň?

Ja by som chcel robiť ďalšie zoradiť podľa dátumu, v ktorých hodnota sa začína s dátumom("01/01/2000 opis"). je to možné?

       var result = await
   (from book in db.booksTable
          where book.IdCategory == request.bookCategory
          select new 
          {
                 Author = book.Author ?? "unknown",
                 Opinions = (from opinion in db.opinionsTable
                 join critic in db.criticTable on opinion.IdCritic equals critic.Id into c
                 from critic in c.DefaultIfEmpty()
                 orderby critic.order, HERE additional orderby
                 where book.id == opinion.IdBook && critic.order != null
                 select new
                 {
                        Value = opinion.Text ?? "empty",
                        critic.Topic
                 }).ToList()    
          }
   ).ToListAsync();

   my Value:
   "example"
   "Sample description1"
   "01/12/2021 other description"
   "Sample description2"
   "05/01/2021 other description"
   "09/01/2000 other description"