Sumproduct/sumif

I'm trying to create a table which, from a data report, will sum the number of hours specific roles have worked on specific projects.
The issue I'm trying to get around is that some roles need to be added together into one cell and some projects are made up of multiple job codes which also need to be added together.

I initially named the range for the multiple job codes associated with the project. I then used the following formula to add the multiple roles and job
=SUMPRODUCT(MONTH!$I:$I,--ISNUMBER(MATCH(MONTH!$G:$G,{"Account Manager", "Architect"},0)),--ISNUMBER(MATCH(MONTH!$D:$D,JOB NAMED RANGE,0)))

This was fine for three months of data until I started the current month and I was getting an error message:
"Excel cannot complete this task with available resources. Choose less data or close other applications."

I then broke the links to the prior months so it would just do the formula for the current month but still got the same message and read on a forum that this could be due to the large data and volatility of SUMPRODUCT- is this correct?

Then, I tried to use a SUMPRODUCT(SUMIF) by naming the range of roles and job codes
=SUMPRODUCT(SUMIFS(APR!$I:$I,APR!$G:$G,Data roles,APR!$D:$D,ADMIN jobs))
However it's either returning nil values or not adding everything up and I'm not sure why as the data is consistent.

I hope this all makes sense...Any help would be very appreciated

Thanks