From reading the brochure, the Magnet Explorer fund invests in a set of actively managed funds, so to a large extent this all depends on whether you believe active fund managers can outperform indexes.
It’s generally agreed that active management does not provide superior returns in mature markets but with developing markets like these, fund managers can (theoretically) get greater returns by taking advantage of mispricing in these less efficient markets. So by going the Magnet route you are basically taking a bet that the fund mangers can exploit inefficiency in the less developed markets to gain superior returns and that these returns outweigh the management charge.
Alternatively, you could just buy ETFs for the markets concerned (e.g. products like IFF.L, LTAM.L, BRIC.L - Russia and India ETFs are sold on the NYSE, or something like IEEM.L) and sit back and enjoy the whole market gains or suffer the losses, and also benefit from low expense ratios. (You might also want to read some of the articles on developing country ETFs on before you go this route).