Add more fish?

[New Boy]

I’ve currently got a 190 litre (50 US gallon) tank with 4 small BP’s (2-3 inches), 6 labs (lions cove), 7 barbs (tiger), 1 bristlenose and 2 raphael cats. Filtration is 1600 litres per hour and the tank has been running for about a year. My question is can I add 3 more barbs?? According to a magazine in the UK called ‘Practical Fishkeeping’ you can stock up to 2 inches per Imp gallon after six months so I’d be ok. Never had Nitrite or Ammonia probs [touch wood].
I’m planning to move all of my fish to a 400 litre tank (106 us Gallon) mid next year.

Thanks
Andy