Additional ISA investment query

Cypruseast

Hey folks Happy New Year to all!

So start of year investment review and am a little bit pickled in terms of what to do...

I have approx £140k invested in my ISA and have the following funds currently.
SMT
PCT
BGS
BRSC
JEFI

Its done very well over the last while and given I’ve been in SMT & PCT for over 5yrs now that has done particularly well. I will de-risk my position in SMT at some stage, but I like the ways it’s managed and am confident in the managers there. 

So I have just dropped in another £20k into my ISA account and that alongside dividends gives me about £21k to invest.

I want to ensure I am reasonably diversified and had considered the following areas to work alongside what I already have:

China
Biotech
UK - based on some hopeful long term upside after Brexit/Covid etc.
Global - to offer a little bit of a safer spread.

I feel that 4 funds with only £21k to invest is maybe one too many given I already have money invested in 5 funds - so possibly one will drop out anyhow. In terms of timescales, I don’t need access to this money anytime soon so have a long term outlook on it all.

So in terms of my thoughts so far I have identified the following (ps have always rightly or wrongly focused on Investment Trusts) 

JP Morgan China Growth & Income 
Obviously has done very well but also I doesn’t have as much overlap on investments as some of the other funds I’ve considered e.g the BG funds.

Henderson Opportunity Trust
Uk option and I like a lot of the companies they’re invested into and have previously held shares in some of these companies so know the performance and potential.

Biotech Growth Trust
Keen to have a bit of exposure in this area and there are few other absolute stand out funds.

Global 
No idea at this stage...

Ok so what’s anyone’s thoughts? Is there merit in just increasing investments in some of my existing funds (other than SMT or PCT where I feel I have enough exposure here). Or has anyone any other thoughts of funds that may better balance and offer the spread I am looking for...

Thanks for reading.