this is ordered, coming from 66-info documentation
By default the first service displayed is the first service started, the second one is the second started and so on.
the first number found between '()' bracket is the corresponding pid of the service.
So, in your case the first services started is dbus-log then tty then zfs and so on.
(681,Enabled,longrun) dbus-log
in this case 681 is the PID of the dbus-log service which is a longrun. So if you 0 for a longrun or classic service that mean that something is wrong.
Services are started following the dependencies declaration, so dbus-log is started before dbus because dbus depends on dbus-log (equal for sddm and sddm-log).
Now we do not have dependencies between classic and 'atomic,bundle', that's why you can have classic 'inserted' between two atomic services.
Well, this thread show me two misconfigurations of daemon. The first one is my fault, the second one come from you.
Dbus should be started before sddm. Well, my bad i didn't declared dbus as dependencies in the sddm service file declaration and sddm should be a longrun instead of classic to be able to have dependencies for it.
The second one concern your wifi service. i didn't realize that you starts dhcpcd with -b options. In this case, you should use oneshot instead of classic service type because you don't have nothing to supervise, this is exactly the role of a oneshot service.
Be aware(need to put this somewhere in the documentation) of one thing, when you change the type of a service keeping the same name, you need first to disable and stop the service from the tree then enable and start the new one. For the moment a conversion file format do not exist with 66.