4 stroke engines have 2 TDCs for #1, and the other 5 cylinders as well, all have a compression stroke TDC, and an exhaust stroke TDC
A V6 engine's crank is balanced so 2 cylinders are at TDC at the same time, these are called Match Pairs
Matched pairs on the 2.9l, and MOST V6s are
1/5
2/6
3/4
This also explains the firing order
1 4 2 5 3 6
When you split the firing order and put one half below the other you get the matched pairs on ANY engine, 4cyl, I6, V6, V8, V10, ect.....
1 4 2
5 3 6
1/5, 4/3, 2/6
The Cam and Valve timing sets #1 compression stroke and #1 exhaust stroke, and #5 would be the exact opposite as #1's Matched Pair
So if cranks timing mark is on TDC and distributor rotor is pointed at #1 spark plug wire, then you have a 50/50 chance of rotor being in correct position without any other tests
If its a No Start then setting rotor 180deg off, so pointed at #5 then it will either start or its not a distributor timing issue
Obviously testing #1 for compression stroke takes the guessing off the table which is always best, if you can, lol
But unless the crank's TDC mark is off you only have 2 positions to test for the rotor, #1 and #5