I looked at a few MLB team game logs from 2018. All had stretches of streakiness that SIM owners would have complained were unrealistic.
Yankees W3, L5, W4
Oakland W6, L3, W6
Cubs W5, L5, W5
Astros L5, Won 6 of 7, L5
Braves W5, L4, W4 and a W6, L4, W6, followed by losing 4 of next 5
Phillies W3, L4, W5
The Rays had some major streakiness. Within their first 44 games of the year they had win streaks of 6 and 8 and losing streaks of 4 and 8. Another stretch of the season saw them lose 6 of 7, then W6, L3, won 6 of 7, L8