How to convert excel aggregation/consolidation to google sheets

I'm a reasonably high level excel user
I'm currently doing some work for an organisation that uses google sheets and I can't find a way to convert key excel function
This is how to aggregate cells in a summary worksheet that sums the equivalent cell in a range of worksheets where that worksheeet range may vary
For context and by way of an example I might want to aggregate values from active projects
The project sheets are identical in design and I want to aggregate for live sheets only to a summary sheet of the same design
However live projects come and go so I don't want to change individual formulae as sheets are dragged in and out of the range
Excel can do this brilliantly with a variation of the =SUM(a:y) function that takes the form
=SUM(Start:End!A1) where start and end are blank sheets and !A1 aggregates every A1 cell in the worksheets that lie between the Start sheet and the End Sheet

I can't replicate this in google sheets
Any bright ideas??????

Thanks