`rsync`: trailing slash vs wildcard

Suppose I want to sync the contents of a directory (source_dir) using rsync without creating a directory named source_dir in the target directory. I can do this using rsync source_dir/ target_dir or rsync source_dir/* target_dir. Is the following correct? The former will sync everything, including hidden files and source_dir/.. Using the latter the shell will expand the * to every every non-hidden file in source_dir and thus every non-hidden file in source_dir will be synced. (I'm asking mainly to check my understanding, but the XY problem behind this is that rsync -t source_dir/ target_dir tries to set the time and I want to avoid that without using -O.)