I'm almost certain they'd sell more units and make more profit if they changed it to one smaller/simpler enclosure (i.e. prosumer) and one bigger high-end enclosure.
Not necessarily. Cherry picking out all of the potential upsides isn't a balanced analysis of what will happen to the product line up ecosystem. This ignores several very real factors.
1. You going to create more expensive super-max model ( drive pricing up). Once you prune off the super-max enclosure the number of units sold will go down from Mac Pro numbers. That means the number of users you will have to amortize costs will go down ( fewer people paying for more custom designs. ). You also have increased support costs because now have products to cover and configurations to test/certify/diagnose. Also will have yet another team with is largely constructing the same thing CPUs/memory/etc. the only minor variations here are a couple extra support chips and more/less wire routing. More parallel design teams, more costs.
So most likely the "overhead tax" assigned to the "super-max" users will go up much more than it will on the "mini-tower" folks.
The spin here is that magically more users are going to flow in to fill the gap. That's isn't particularly likely. Apple will still have 4-6% of overall market. If the "super-max" crowd is 1% of the overall PC market then 6% * 1% is 0.06% of the market. That's not a big group to chase after for a multilbillion a year corporation. Bubba Gump's custom PC internet business... yeah alot, but for Apple no.
Even if you do get folks to flow into "super-max" market you are also going to get folks flowing out. Right now Apple has decent pricing for folks who are in the middle of the targeted market. Those folks will see box increase in costs for value they don't really leverage.
If look at HP/Dell/Lenovo there super-max boxes are higher. The farther up their product lines you go the more and more Apple mark up margins start to match there or even look a bit better. Same diminishing small market segment factor drive up prices on their side too and they sell many more units (because folks want Windows and to lessor extent but significant in this specific hardware market, Linux. )
2. The mini-tower model is going to cannibalize a subset of the iMac market. Again that doesn't increase overall profits at all.
Additional, secondary effect of decreasing the number of LCD panels sold by Apple which will have cost increases along parts of other lines since impacting their economies of scale. Even more costs if force Apple to jump back into much more broadscale commodity monitor business.
Even though the base Mac Pros sell less in number because priced a bit high compared to mini-tower alternatives their development costs are very low because just an extremely minor change from what the mid/upper Mac Pros. So as long as they grow the Mac Pro chassis base some, then they are lowering costs aggregate costs (hence making more profit).
Decouple the more base level Mac Pros from the upper end versions by turning them into mini-towers and the price will likely have to fall back. You'd have to increase volume just to tread water. The amount of profit is lower per unit and have increased cannibalization by significant amount.
Likewise support/certify/diagnosis queue is bigger and more expensive because have split one product into two.
Don't your breath to see Apple do this.
Yeah sure Apple could build a Super-max workstation. They could also build:
2U , 4U servers
Grid in a cargo container boxes
a smaller screen Macbook to crack the sub $800 barrier.
A toughbook like ruggedized Laptop
PCI expansion boxes
RAID boxes ( oh wait they did and canceled that)
etc. etc. etc.
In short, Apple operates differently that most of the PC vendors. Many of the PC vendors have super low margin models at the lower product lineup extreme and super high end margin models at the highest end product lineup extreme . They try to blend the lows with the highs to get an acceptable rate.
Apple puts approximately the same margin on everything. Low and high. The high end stuff isn't there to prop up the low end stuff and the low end stuff isn't there to drag down the high end stuff. Apple's Mac business is oriented toward finding the sub 8% of the personal computer that wants to buy the subset of possible products they make and selling them to just those folks. They aren't even trying to sell something to everyone.
So when folks come up with laments of "well they are missing me" .... that doesn't matter. "Well there are 10,000 people like me" ... still doesn't matter. Apple spins like they are small company but if there aren't significant economies of scale in it they aren't doing it. 10,000 folks isn't huge scale.
As the overall PC market grows by 10's of millions a year 8% becomes an increasing larger number (relative to 10K-100K range. ). In that sense, Apple can stretch claim "small" while still not trying to filling smaller niches in the market.
