Hi CClem -
<<" I didn't realize there were so many options for routes.">>
There are a lot, and one way to sort them out is to look at a topographic map with hiking trails marked.
I gave you thorough instructions on how to do that in your earlier thread.
If you compare your suggestions in this thread with the suggestions from Mark immediately above, using that topo map, you'll see that your suggestions are more strenuous, with greater altitude changes for little benefit on scenery. All three of your days in this thread have that issue. Possiblty, that is because you chose to make a linear journey. That is more practical in less alpine regions, such as the Emmental, where inn to inn hiking is a tradition.
Mark has given options that take better advantage of the transport system to gain or lose altitude, and cover distance, while getting you the scenery from the higher alpine trails. That is a benefit of the transport density in the region. They are not a linear trail, as you laid out in your routes, but you are still going inn to inn.
And, his Day 3 takes you from Männlichen to Kleine Scheidegg in the definitely better direction. See attached). It lets you feel the Eiger grow over you as you hike. Awareness of the history of the North Face of the Eiger (in Geman, die Nordwand) , nicknamed die Mordwand ( the Murder Wall) adds to the feeling.
Looking at his day 3, on a map, you can see that it is actually not very convoluted.
map.geo.admin.ch/?topic=swisstopo&lang=e n&bgLayer=ch.swisstopo .pixelkarte-farbe&catalogNodes=139 2,1538,1396,1430,1436& layers=ch.swisstopo.sw isstlm3d-wanderwege&E=2641788.7 3&N=1160985.47&zoom=6
It is a circular route. But, you don't have to return to Grindelwald. And, to continue with your thought about options, there are at least two variations you can consider.
As he proposes for day 3, you will make the not very difficult climb from Kleine Scheidegg to Eigergletscher, then continue on the Eiger trail down to Alpiglen.
You can also ride the cograil train from KS to Eigerglettscher, if you choose.
Second option...definitely more convoluted -
Once at KS, take the cograil train down to Alpiglen. Then hike the Eiger trail up hill about 400 meters, and across to Eigergletscher. Train or walk down to KS, and return to Grindelwald by train. Or, if you want to go to a different inn, ride down the Wengen or Lauterbrunnen.
Advantage- you don't beat up your knees as much with the 400 meter descent to Alpiglen. Disadvantage - you don't face the valley as you make the climb. On the way down, you face the valley more. Since the trail has switchbacks, that is not precise comparison...the switchbacks do let you see in all directions, but the differnce may be meaningful.
A bit more food for thought (or your stomachs) . The mountain in at Alpiglen is famous for it's Käseschnitte.
What starts out as simple melted mountain cheese on toast ends up with wine soaked bread, and a large number of added toppings. It is very large, and a goal of the journey for some.
Roughly translating some of the first text from that link:
"Und auch das Restaurant Alpiglen hatte schon offen, so dass ich auch noch meine Käseschnitte geniessen konnte."
"And Restaurant Alpiglen was already open, so that I could still enjoy my Käseschnitte."
As an aid to planning, you should be aware thta you can leave luggage at Grindelwald, Lauterbrunnen, and Wengen stations.