Here's another idea.
You know how for the 1992-1996 Young Indy they began with "1908 and 1916", one using Corey Carrier and one using Sean Patrick Flannery?
Well for the new series (if they are made) I propose that the way they go about it, is hire an unknown child actor (John Doe for my example), Corey Carrier, and Sean Patrick Flannery and even Harrison Ford and then commence filming!
Say, for example, season 4 of Young Indy is commenced in 2009, well this is personally how I would do it:
Season 4 - 2009
Indiana Jones (1908) - John Doe
Indiana Jones (1916) - Corey Carrier
Indiana Jones (1938) - Sean Patrick Flannery
Indiana Jones [age 60] (bookends) - Harrison Ford
then do filming with John, Corey and Sean all simultaneously until you have like 5 '08 episodes, 5 '16 episodes and 5 '38 episodes. '08 is about Indy's early adventures with his parents and Miss Seymour (Margaret Tyzack wouldn't happen to still be alive? <_<) '16 can be about his war years and '38 can be about his archaeological years... that way they can also satisfy the picky people who demand archaeological adventures out of the show. Then go a few seasons until John Doe's character of Indy becomes 16 years old, then stop for him. Then continue with Corey and Sean. Then eventually stop with Sean and then eventually with Corey...
That is the first way I would do it... now, another way I might do it (the more reasonable way) would be to:
Season 4 - 2009
Indiana Jones (1908) - John Doe
Indiana Jones (1918) - Sean Patrick Flannery (skip the first two years, since they're so packed)
Indiana Jones [bookends] - Harrison Ford
And hope Sean still can act as young as he use too... and leave out Corey...
... OOOOR you could use method 1 but just leave out Sean... or you could leave out John Doe... or...
well... either way you do it... let's try not and split hairs with the "changing actors will be stupid" response... who cares if they look a little bit different... I'd rather have more episodes and look over the fact that they may not look the same, and just enjoy the episodes!
I am a true fan... some may complain that I'm not a fan enough to not care that the look is the same...
no... on the other hand... I'm so much so a true fan that I want Young Indy episodes SO badly that using Corey as the teenage Indy along side the Sean episodes isn't such a big problem!