I want to earn the Meraki cert, but I'm concerned about the exam questions requiring calculation on these formulas. Would the exam questions require correct calculations as documented, or as I suspect the correct formula should be?
I think you are right and the documentation is wrong.
The formulas are inconsistent. The easiest check is a full mesh with two hubs and two links each. The tunnel count per MX has to equal the total tunnel count. I assume that they just forgot the "to the power two" for the L1 in the first formula.
I’ve been thinking about this, and have to agree with @MG41372 . It does look like the total tunnel count for a full mesh with hubs needs the L1 to be squared. Take for example three hubs, if they each have one uplink the formula works, and gives the answer 3. However, consider if each hub has two uplinks, then each of the three hubs will try to build 4 tunnels to each other hub (W1-W1, W1-W2, W2-W1, W2-W2) - whether it succeeds or not is all part of the design, but this is what the hubs will try and do. Quickly you realise this is a total of twelve tunnels, so the L1 must be squared to make the formula work
But my bigger concern is with the exam questions, since the ECMS2 course final exam scores its question using the calculated value from the incorrect formula as documented in the course material as well as the posted Meraki doc.
I have reached out to Cisco regarding the doc and course materials a while ago, but have not received any responses.