Your assumption is based on players only hatching one at a time but regardless of how many you are hatching simultaneously distance still ends up being less. For sake of arguement assume an even distribution of eggs so 1/3 of eggs received are 10 km eggs you would be walking An average of 17 km per 10 km hatch vs 10 km per 10 km egg if you keep deleting other eggs to get them.
It does totally change the game because now you can farm for the more rare Pokémon in the 10 km eggs.
Honestly I just go gifts that will give me alolan eggs that are from different states ( US person here) otherwise Iâll just open the gifts when I have 9/9 eggs if theyâre from my state.
When I get an open egg spot, I open an international present to get a new egg. Then when that egg hatches, I trade it to collect the distance kms towards getting pilot badge.
Nice, thought about doing that. Itâs a great way to get that badge faster.
All nine of my eggs are Alolan International. That will change once Gen 4 comes out, but there is nothing in current egg pool that helps me, so I stick with foreign eggs. Last trade I did with my son was like 8000 km for both of us.
I would add people internationally, I just donât add people I donât know personally. Itâs my rule for all video games/systems. Honestly if it comes down to it and Iâm really pressed to get the pilot badge I have a reserve of international PokĂ©mon that Iâll use to trade before I add people I donât know.
They drop easily from the pokestops. Get the 9 and just open all the gifts for the day. No more alolan eggs. Still need a geodude and a vulpix⊠over 30 eggs hatched and not one of those.
Same here 
Currently I am trying to get rid of my 5ks and get 2ks so I am ready for the quest âHatch 9 eggsâ 
Just hatched a Mr. Mime and a Taurus from 7km egg in the gift sent from US by pokefriends.
I just got a Tauros!
Nailed my first ever Kanga! Answered Prayer 
7KM Egg still provide, no matter how low the percentage is. Perhaps some could call it their Lucky Egg 
Got Mr. Mime yesterday and Kangastahn this morning. Then Mewtwo this afternoon to finish out Generation 1.
Hatched 4 more eggs still no Kanga, 
just need Kanga to complete my gen 1 Pokédex
just try and try and try, until you have one.
just nailed one from a 7km egg, though a not so good stat, at least I had one already.
And the egg is from a local friend not from overseas so it means the 7km egg does not have to come from where the regional pokemon is usually found.
Perhaps you could PM me your trainer code, who knows, my luck might be shared with you too!
I had to hatch 13 eggs before I got what I needed on #14 and 15.
Hopefully eggs #12 and 13 will yield what I need
Iâve only been running 2 incubators since event started but my son has 5 cooking right now. I play a lot more than he does though.