The schedule of artists and engineers is not aligned as the project was waterfall.

Since the work of both artists and engineers is needed to create an increment, shouldn't they be on the same Development Team?

Hi Ian, thanks for helping!

Yes, they are now in the same dev team. But they weren't not as working in waterfall.

Only engineers are working on the increment. Artists have done the artwork for this increment long time ago and are working on the artwork for later sprints.

It is so abnormal tho, so I want to align them altogether.

This is a "bad smell" regarding Scrum.   The term is called Local Optimization, and it refers to the practice of keeping specialists busy with their specialized tasks, which does not help move any work product to "done", and simply results in creating more inventory of unfinished work.

Your "artists" may be done with their artwork for the increment, but the items are incomplete from an end-user perspective.   You need to shift the focus from those doing the work, to the actual end work product.

What does your Definition of Done look like?

If people aren’t working on the increment, then they aren’t really members of the Development Team. What can each person who aspires to the Development Team role do to escape their old role restrictions? What can they do now to help develop each Sprint increment? Looking at the work which remains to be done, what useful skills does each individual person have to offer, and what new skills might they be able to learn?

creating more inventory of unfinished work

This is a very important pointer from Timothy and I want to re-emphasise it. Inventory is waste. You say the artists are doing artwork for later sprints. But in fact, they're doing artwork for what you think may be later sprints. With changing requirements, there is a very real chance that what the features they're designing right now will not make it into the product. In which case you wasted a lot of time and money.

Thanks all of your replies!

I understood the risk and problems of doing this, and I explained the artwork might not be valuable as planned cause we are working in a complex environment.

Now I just suggest artists to support the engineers to deliver the increment in each sprint first, and shift their schedule by suggesting them to review the artwork of current sprint or taking leaves (xmas is coming, haha), just for slowing down their progress.

"creating more inventory of unfinished work" create more complexity, so I can only communicate with them, I guess.

Don't know if it works, any idea regarding turning waterfall in agile?