It also does not help that WMC record two programs in a row on the same channel as two different recordings that will overlap with record early and/or stop recording late.
As you suggest... maybe you need more tuners if you want to record more programs individually than you have tuners to accomplish that, even if you have the Ceton card (as I do as well).
If you use the Guide to set your recordings, either one-off or series, then each recording is for one program. Why would you not want this? It makes it easy to set recordings, and it makes it easy to play back from the list or your recordings.
If your problem is that you need more then 4 separate tuners can provide (meaning you need more than 4 recordings going on at the same time), then you need a different approach to recording, or you need more tuners.
Why not just allocate one tuner for consecutive programs on one channel (say for primetime 8-11PM on Thursday night), by manually setting a recording for that 3-hour block... as one block... instead of using the Guide to record each hour or half-hour individually by program name? Just manually "add recording" (like you'd do with an old-fashioned VCR), give it a name like "Thursday NBC primetime" and be done with it? That will leave your three other tuners free for other recordings during that block?
Sure, this approach means you will not be able to play/delete individual programs during that block by name but rather will have to use fast-forward or 30-second skip to navigate, but if you feel that's the lesser of two evils then do it that way.
Me, I have no problem with 4 tuners satisfying my recording/viewing needs.
Now it's true, I also have a separate ATI TV Wonder 650 PCI 1-tuner OTA/ATSC tuner card in my HTPC as well as my Ceton card. The Ceton card is fed by my TWC/LA coax cable, and my ATI card is fed from my roof OTA antenna. So maybe that's a luxury option you might not have. I use my ATI card for all network channel recording (as long as there's not a need for two or more recordings at once, in which case I schedule the overflow on the Ceton tuners).
I prefer the OTA/ATSC versions anyway, because the HD quality is superior. Here in TWC/LA land the local networks are recompressed and delivered at a reduced bitrate and quality, and I prefer the unrecompressed original OTA video quality.
But I've never had a conflict of wanting to record so many programs at one time that 4-tuners on the Ceton card ever was insufficient, which means I needed to record more than 4 programs at one time... which is virtually unheard of for me. But, your TV habits may be different but this really might justify a revision of your recording scheduling technique.
Note that you can also schedule recordings for later repeat airings of cable shows, which often occur... in case there is flat out an impossible scheduling conflict where you really needed to have five first-run recordings at once. Why not just manually schedule things to circumvent this problem, by looking ahead in the Guide and manually scheduling a later airing for recording?
The Ceton 4-tuner card and WMC certainly beats a 2-tuner DVR from TWC/LA in my opinion.