It's possible through trade copiers. https://www.socialtradertools.com/trade-copier/ https://flowbots.ninja/product/replikanto/?v=7516fd43adaa I'm sure there are more. Just google "trade copier".
You ask for a block account from your broker. You give him the allocation %, and what accounts are included and then the back office allocates them or some software does it auto. All done via one platform, one login.