Imgnz,
Griffiths for Mullaroe has plot 2 – Patrick Scott with 25 acres, 3 roods, 0 perches, rented from Rev William Black. Described simply as “Land”. IE No house & no offices (outbuildings).
Below that on 2a you have Mark McDonnell, renting from Patrick Scott “House and gardens.” 1 rood and 15 perches (typical for a labourer. That was to grow his vegetables).
So that shows Patrick Scott using only the land on plot 2, and Mark McDonnell renting the house there from Patrick. No sign of Patrick Scott living there at that date. To me the record is quite clear that Patrick Scott was not living in Mullaroe in 1857.
The tithes were a tax on land, used to support the Church of Ireland. Deeply unpopular and eventually abolished in the 1850s. But the point is they were not a census. They only listed folk with land. So labourers, shepherds, tradesmen, servants, lodgers and anyone who did not have land was not listed. (A few perches to grow vegetables wouldn’t get you listed in the tithes). Since the majority of the population then were not farmers (most being labourers) it’s not unusual to find them in Griffiths but not in the tithes. Even Griffiths didn’t list everyone either. Properties of too low a value to be worth assessing were excluded, and obviously lodgers, servants and others living with someone else are all excluded.
To add a little extra confusion, the tithes were compiled in Irish acres (sometimes called Plantation measure) but Griffiths is in statute acres. You can use this link to convert one to the other:
https://www.convertunits.com/from/acre/to/acre+[Ireland]
That said, the tithes really only included land that could be used for tillage. Grazing land and so on was excluded, whereas it was included in Griffiths. It can therefore be hard to compare the two accurately.