Triathlete magazine's Essential week by week training guide

Disclaimer - I am not a coach

Since you are not following a coach's plan customized for you, split them up.  The only "rule" I would follow is don't put your long sessions within 24 hours of eachother.  For shorter stuff frankly, I don't think it makes a whit of difference whether you bike/swim on one day or run/swim on one day.  ETA, I also don't think it matters if a Tuesday has 4 hours between biking and swimming and 1 hour for running.  I wouldn't expect any day to be similar time wise to another

Although I will say a swim/bike brick now and again is a nice eye opener

I like the book and used it a bit.  Followed it for last springs HIM.  Level 4 I think?

What you describe is a shortcoming (IMO) that I have noticed.  I did not like moving up for the same reason.  swimming AND biking on the same day called for some long days.  Then you get a 'short' day of running only.  Seemed to make more sense to mix running and swimming on one day then bike then next.

However, after some experience, I don't see why you can't move the swim to the run day and keep cyling by itself.

ALSO, have you noticed, that highest level of a group has the same, if not MORE hours (peak week) than the lowest level of the next higher group?  (If that makes sense).  Also, some of the higher Oly plans have more hours than some of the lower HIM plans.  Even some of the long bike and long run times are close to the same (the long stuff is what I focus on in a plan).

So there is also options there.

I'm not sure if I answered anything or just made it more confusing, but I'm not sure what you were asking in the first place.  I basically know that book inside out, if you want any more opinions/thoughts.

The peak week should have about a 3:30 - 4 hour long bike.  That sounds about right for an HIM.  That leaves about 4 hours left for the rest of the week.  A couple 90 min rides and a brick (this IS the peak week, mind you).

The long run should be about 90 min to 2 hours IMO.  That leaves 90  min for the rest of the week.

The swim?  7,800 breaks down to about 2500, 3x that week.  Sounds about right to me.

Again, this is PEAK week.  Level 5 is also to get you pretty competitive.  You can do much less if you just want to finish safely with a respectable time.

One more thing...  I was actually thinking about doing the level 8 Oly plan (or whatever is the highest of the second group) for my next HIM, but stretch out the long runs and bikes to match those in an HIM plan.

I figure that I could work on the speed for an Oly, but still get in some long stuff for the HIM.  Then I would be good for either.

If you really look hard enough, even though the book has something like 48 plans, a lot of them are repeats or modifications to the same plan for the different length races.  They have the same outline, but just increase the length of workouts depending on the length.

At a quick glance it just looks like they are recommending 2 a days.  I have 2 a days all the time.  And with that plan, you have an easy day after the 2 a day.  So that makes sense to me.  It's really not that long of a day if you think about it.  Wake up early, go swim, go to work, then get your bike in the pm.  done before 6-7.

They do take some getting use to though.

I agree 100% if you can do it like that. 

I know I have a tough time getting up that early (no will power!), so many times I have to do one at lunch and one after work, or do a brick after work.  Doing a bike/swim after work could make for some long nights...