The picture that I got from reading about Tramiel in the early years of Commodore doesn´t fit into what happened with Atari in the 90s. If 1984s Tramiel had AMIGA he wouldn´t have built the machine we love today. Tramiels Amiga would have had only 2 custom chips and no multitasking in the OS. It would have come out in January 1985 and shipped in March. Something like the Amiga 600 would have entered the market in 1988. Tramiels values would have been preserved by a new management. Tramiel retires. In 1990 Amiga would have had a DOS mode that could make use of all 4096 colors but most Software would have ignored that. In 1995 Amiga would have had its own x86 compatible CPU and Amiga would have ported Workbench to Windows NT. 1996 Amiga would have had realtime truecolor 3d animation at $2000. Sadly it wouldn´t be very popular due to poor marketing.
Oh and Atari would still be kicking Sonys ass and Playstation II wouldn´t have been built because of low market potential.