Yes, the others were done by Drew, starting with the (now) 10th Anniversary poster. It was used in overseas marketing for Raiders (and can be seen on Cheers when Sam is running around Italy looking for Diane and Frasier—though I'm sure that was a backlot). Struzan did a lot of Raiders comps as well. Amsel was chosen first, and then chosen again to do the re-release poster to echo more of the fun of the film. Struzan didn't even start out with Temple of Doom. The Style A for ToD was Bruce Wolfe. But again LFL wanted a more fun/adventurous campaign and Drew did his ToD. He has been considered the Indy artist since. Though Mark Raats did an awesome poster for Raiders' anniversary screenings.
Don't even get me started on Dial of Destiny's advertising! In a film centered all around the theme of an aging hero, they were afraid to SHOW an aging hero! Most people didn't even realize there was a new Indy film! He was kept in shadow while ancillary characters were prominently displayed in photoshop dreck. It wasn't until Stella's work was released that Indy was shown. And even then they mucked with the art. Why remove Klaber's gun from Stella's work but keep it in the photoshopped mess?